COURSE PRICE: $24.00
CONTACT HOURS: 3
This course will expire or be updated on or before June 3, 2013.
ABOUT THIS COURSE
You must score 70% or better on the test and complete the course evaluation to earn a certificate of completion for this CE activity.
ACCREDITATION / APPROVAL
Wild Iris Medical Education, Inc. is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation.
Wild Iris Medical Education, Inc. (CBRN Provider #12300) is approved as a provider of continuing education for RNs and LVNs by the California Board of Registered Nursing.
Nurse practitioners may apply these contact hours to pharmacy continuing education and prescriptive authorization.
Wild Iris Medical Education, Inc. provides educational activities that are free from bias. The information provided in this course is to be used for educational purposes only. It is not intended as a substitute for professional health care. See our disclosures for more information.
Copyright © 2010 Wild Iris Medical Education, Inc. All Rights Reserved.
COURSE OBJECTIVE: The purpose of this course is to provide caregivers with an overview of type 1 diabetes and its management, impact, and complications.
Upon completion of this course, you will be able to:
Diabetes mellitus, more commonly referred to as diabetes, is a pathologic condition in which the body is unable to properly store and process blood glucose. The monosaccharide (simple sugar) glucose is a critical carbohydrate utilized by cells as a source of energy. Normally, cells absorb circulating glucose from the blood in response to stimulation by insulin, a hormone produced by the pancreas. In the case of diabetes, either a decrease in the concentration of circulating insulin or a decrease in the body’s response to insulin impairs this function. As a result, blood glucose is not properly absorbed by cells and accumulates in the blood, leading to a condition known as hyperglycemia, or high blood glucose levels.
While temporary hyperglycemia with only slightly elevated glucose levels is often benign, acute hyperglycemic episodes with extremely high glucose levels is considered a medical emergency that can result in life-threatening dehydration or coma. Similarly, chronic hyperglycemia may lead to serious complications such as renal failure, neurological damage, or cardiovascular damage.
Although diabetes is a serious disease, patients with diabetes can take several steps to control their disease and thus lower their risk for complications and premature death.
The World Health Organization estimated the worldwide prevalence of diabetes was 171 million persons in the year 2000, the most recent year for which this data is available. Specifically, in the United States, the American Diabetes Association estimated the prevalence of diabetes to be 23.6 million (7.8% of the country’s population) during 2007. In addition to adults, this figure includes children and adolescents, populations in which the disease is increasing with remarkable frequency. Importantly, over 5 million people were found to have undiagnosed diabetes, suggesting a large proportion of individuals with this condition go untreated (CDC, 2007).
Although diabetes affects males and females similarly, racial and ethnic disparities have been identified. National survey data from 2004 to 2006 indicates that the prevalence of diabetes in non-Hispanic blacks is nearly twice that of non-Hispanic whites (11.8% versus 6.6%, respectively). Hispanics also seem to be more susceptible to diabetes, with a prevalence of 10.4%. The prevalence of diabetes among Asian Americans was found to be 7.5%, similar to that of non-Hispanic whites.
The economic impact of diabetes is sizable; in 2007, the total costs of diagnosed diabetes in the United States were approximately $174 billion. Although the majority of this amount ($116 billion) was attributed to direct medical costs such as medication and hospitalization, $58 billion was due to indirect costs, including disability, loss of work, and premature mortality. The average medical expenses for patients diagnosed with diabetes were 2.3 times higher than individuals without diabetes.
Even more significant than the economic impact of diabetes are the high morbidity and mortality rates associated with the disease. In 2006, diabetes was the seventh leading cause of death in the United States. Deaths in which diabetes is the underlying cause often occur as a result of the many complications associated with the disease. For example, the risk of heart disease and stroke are approximately 2 to 4 times higher in patients with diabetes. Other morbidities that occur at a greater frequency among patients with diabetes include hypertension (high blood pressure), blindness, kidney disease, neuropathy (nervous system disease), and limb disease resulting in amputation.
Although several types of diabetes are recognized, the vast majority of cases are categorized as either type 1 or type 2. Type 1 diabetes (formerly referred to as insulin-dependent diabetes) occurs from the body’s inability to produce insulin. To overcome this, patients with type 1 diabetes self-administer insulin in order to maintain normal glucose levels. Because of its propensity to be diagnosed in children, type 1 diabetes was also previously known as juvenile diabetes.
Unlike type 1 diabetes, patients with type 2 diabetes produce insulin, but their cells do not properly respond to the hormone. This is the most common type of diabetes, accounting for 90% to 95% of all adult diabetes cases in the United States. Type 2 diabetes begins as a condition referred to as insulin resistance, in which the body’s cells do not properly use insulin.
|Preferred Name||Former Name|
|Source: NIDDK, 2010a.|
|Type 1 diabetes||Juvenile diabetes; insulin-dependent diabetes mellitus (IDDM)|
|Type 2 diabetes||Adult-onset diabetes; noninsulin-dependent diabetes mellitus (NIDDM)|
|Characteristic||Type 1 Diabetes||Type 2 Diabetes|
|Source: Dean & McEntyre, 2004.|
|Time of onset||Primarily in childhood and
|Predominantly after 40 years of age|
|Body type||Often thin or normal weight||Often obese|
|Insulin requirement||Insulin administration required for survival||Insulin administration not required for survival|
|Pathophysiology||Pancreas is damaged by an autoimmune attack;
|Pancreas is not damaged by an autoimmune attack; insulin resistance|
Gestational diabetes, another form of the disease, arises from glucose intolerance during pregnancy. Generally affecting women who are obese or who have a family history of diabetes, it requires treatment in order to avoid complications in the infant. Women who develop gestational diabetes have a 40% to 60% chance of developing type 2 diabetes in the 5 to 10 years following pregnancy (CDC, 2007).
Type 1 diabetes accounts for 5% to 10% of adult diabetes cases in the United States. Unlike diabetes overall, type 1 diabetes is more common among non-Hispanic whites than non-Hispanic blacks or Hispanics in the United States. Asian Americans have the lowest incidence of type 1 diabetes (CDC, 2007).
Type 1 diabetes occurs most frequently in children and adolescents. In fact, it is the most commonly occurring pediatric metabolic disease. The annual incidence of type 1 diabetes in younger patients (<18 years) is 15 cases per 100,000 individuals. According to the American Diabetes Association, approximately 1 in every 400 to 600 children and adolescents has type 1 diabetes.
Interestingly, the incidence of type 1 diabetes varies worldwide. The rate of type 1 diabetes in the United Kingdom is similar to that of the United States. However, overall in European countries, the highest rates of type 1 diabetes occur in the northern part of the continent, while the lowest rates are in the southern region. Even the lower rates of type 1 diabetes present in southern Europe are still greater than those in Asian countries such as China and Japan, which share the lowest worldwide prevalence.
Type 1 diabetes typically presents in children ≥4 years of age, with a peak incidence of onset between 11 and 13 years of age. Despite its propensity to occur in younger individuals, type 1 diabetes also affects adults, where it generally appears in individuals in their late 30s to early 40s.
Type 1 diabetes in adults is often caused by a loss of pancreatic function, resulting in limited or discontinued insulin production. For example, loss of pancreatic function may occur as a consequence of chronic pancreatitis, in which repeated and prolonged inflammatory episodes cause damage or death to the insulin-producing cells of the pancreas (Choudhuri, 2009). In adults, this form of diabetes may also be referred to as latent autoimmune diabetes of adulthood (LADA), or type 1.5 diabetes, a form of the disease with a very similar pathology to type 1 diabetes (Appel, 2009). LADA is considered to be frequently misdiagnosed in adults as type 2 diabetes. Thus, in the absence of traditional risk factors for type 2 diabetes (such as a family history or obesity), patients with adult-onset diabetes should be considered for an alternative diagnosis of LADA.
Unlike with type 2 diabetes, few risk factors have been identified for type 1 diabetes. Additionally, no risk factor has been shown to be singly responsible for the development of type 1 diabetes, suggesting that the disease arises as the result of a number of triggers.
A patient’s risk for eventually developing type 1 diabetes can be quantified by measuring levels of specific biomarkers, molecules indicating that an autoimmune reaction against the pancreatic islet cells is occurring. For example, the presence of antibodies against the pancreatic islet cells, or directed against insulin itself, both are suggestive of an autoimmune reaction. Also, as the understanding of genetic factors that lead to type 1 diabetes increases, gene tests may help to identify patients likely to develop the disease.
One major risk factor for the development of type 1 diabetes is family history. Individuals with a first-degree relative (i.e., a parent, child, or sibling) diagnosed with type 1 diabetes are at a significantly greater likelihood of developing the disease themselves. Between 10% and 13% of children with newly diagnosed type 1 diabetes have a first-degree relative diagnosed with the disease (Achenbach, 2005).
Interestingly, the Diabetes Prevention Trial 1 (DPT-1) showed that the risk of type 1 diabetes associated with family history was dependent upon the relative with the disease (Yu, 2002). In that study, siblings of individuals with type 1 diabetes were more likely to develop the disease compared with parents or children. In addition, another study found that the risk of type 1 diabetes was compounded if both parents or a parent and a sibling had type 1 diabetes, suggesting a marked increase with an increasing number of affected relatives (Bonifacio, 2004).
Genetic factors have also been ascribed to the development of type 1 diabetes. The majority of genes associated with type 1 diabetes are categorized as human leukocyte antigen (HLA) genes; together, HLA genes contribute up to 50% of the genetic risk for type 1 diabetes. Certain HLA genotypes confer an increased risk for the development of type 1 diabetes, while other HLA genotypes are associated with a decreased risk for the disease.
Another major site of genetic association with type 1 diabetes is located within a region of the DNA responsible for control of the insulin gene. Genetic variations within this region can lead to decreased insulin production, thus resulting in type 1 diabetes.
The genetic component of type 1 diabetes is especially notable among identical twins, among whom there is a concordance rate of between 25% and 50%. However, this rate also suggests that environmental factors have a role in the pathogenesis of type 1 diabetes (Achenbach, 2005).
Dietary components are one example of environmental factors that may lead to the development of type 1 diabetes. Among these dietary factors, short duration of breastfeeding and early introduction of cows’ milk to infants are leading candidates. Short breastfeeding duration was suggested as a possible risk factor in the wake of evidence showing that longer breastfeeding may protect children from the disease (Sadauskaite-Kuehne, 2004). The evidence for early introduction of cow’s milk as a risk factor is more controversial, and some studies show no evidence to support this.
Viral infection is another possible environmental risk factor for type 1 diabetes. The connection between viral infection and the onset of type 1 diabetes is unclear, but it may be that viral exposure triggers an autoimmune response targeting the insulin-producing cells of the pancreas. Alternatively, the virus itself may target these cells, damaging them and rendering them incapable of effectively producing insulin. Viruses suggested to play a role in the pathogenesis of type 1 diabetes include Epstein-Barr virus, coxsackievirus, mumps virus, or cytomegalovirus (Mayo, 2009).
Because the exact cause of the autoimmune reaction that leads to the development of type 1 diabetes is not clear (and likely differs among patients), there are no sure ways to prevent the onset of this disease. Current clinical trials are focused on examining ways to prevent type 1 diabetes from forming in individuals who are at a particularly heightened risk of developing the disease. For example, the ability of oral insulin to prevent type 1 diabetes in people at moderate (25% to 50%) risk of the disease is currently being investigated in the DPT-1 trial (NIDDK, 2010b).
Normally, the amount of sugar in the blood is increased after a person eats. This rise in blood glucose triggers the release of insulin, a hormone secreted by the pancreas. The major function of insulin is to stimulate the removal and storage of glucose from the blood in order to allow it later to be used for energy. As a result, blood glucose levels return to normal.
In patients with diabetes, blood glucose is not properly reduced by these mechanisms. For patients with type 1 diabetes, this is because the body lacks the ability to produce insulin. In most cases, type 1 diabetes is caused by an autoimmune disorder that triggers the body’s own immune system to attack, resulting in damage to the pancreatic cells that secrete insulin (Dean, 2004).
Glucose is a sugar that the body uses as an essential fuel. The extent to which blood glucose levels rise is dependent on the amount and type of food eaten as well as other factors, including the rate of digestion. After eating, glucose crosses the gut wall and enters the body’s bloodstream. Because of its chemical structure, glucose absorption across the gut wall is dependent on specialized glucose transporters. The levels of blood glucose are not constant; rather, they fluctuate throughout the day depending on consumption of food and the body’s needs. In addition to food, another primary source of glucose for the body is the breakdown of glycogen in the liver.
Although the regulation of glucose levels in the blood is maintained by a number of pathways, including removal by the liver, chief among these is the insulin pathway. Insulin is a hormone that is produced by and released from specific cells in the pancreas known as pancreatic islet cells. After a meal, glucose enters the pancreatic islet cell through a glucose transporter. When the cell detects the rise in glucose, it responds by secreting insulin into the bloodstream. Once it is released, insulin has a very short half-life due to its rapid degradation by enzymes.
On a cellular level, insulin acts by binding to insulin receptors located on the cellular surface. By doing this, insulin stimulates muscle and fat cells to remove glucose from the blood. Other functions of insulin include triggering cells to metabolize glucose to produce energy (in the form of ATP) and stimulating cells to utilize glucose during protein synthesis. Insulin also triggers the body to store glucose as glycogen for a short-term energy reserve and to store glucose as fat for a long-term energy reserve.
Type 1 diabetes is caused by destruction of the insulin-producing pancreatic islet cells. Because this destruction is caused by the body itself, type 1 (unlike type 2) diabetes is considered an autoimmune disorder. The exact cause of this autoimmune reaction is unclear, but is likely due to one or more of several factors, including genetics, environmental triggers, pathogens (i.e., viruses), and diet.
Over time, as more and more pancreatic islet cells become damaged, the body’s insulin levels begin to drop. Eventually, the body no longer is capable of producing enough insulin to properly manage blood glucose regulation, resulting in hyperglycemia, or elevated levels of glucose in the blood.
Diabetes is clinically diagnosed as hyperglycemia, or an elevated blood glucose level. However, hyperglycemia and/or some of the other symptoms associated with diabetes may also arise from a number of unrelated medical conditions. Therefore, alternative explanations should be explored. For example, many medications have been found to lead to higher blood glucose levels, and removal of such drugs results in a reversal of the condition.
Individuals with type 1 diabetes may present with any of a variety of symptoms. However, patients may also be asymptomatic or experience only subtle symptoms that go unrecognized. Unlike the stereotypical presentation of an overweight or obese patient with type 2 diabetes, patients with type 1 diabetes may appear healthy and have a normal weight. Conversely, a young lean person may present with a sudden onset of several symptoms at once.
A diagnosis of type 1 diabetes may occur as a result of a routine health screening and blood work. Alternatively, observation of hyperglycemia during other medical examinations may alert the clinician to the possibility of type 1 diabetes. Secondary symptoms (such as fatigue, weight loss, or blurred vision) that appear to be otherwise unexplained may also prompt a clinician to test for the presence of diabetes. Unfortunately, some patients are not diagnosed with type 1 diabetes until they experience a complication of the disease, such as cardiac failure (a heart attack or stroke) or poor wound healing.
A suspected diagnosis of type 1 diabetes prompts a thorough physical examination of the patient. This examination should include a complete medical history, especially addressing the presence of risk factors such as family history. Current symptoms are also evaluated. Because they can be subtle, the patient may require questions to increase their awareness of the presence of these symptoms. For example, the patient should be asked if they have experienced an increased need to urinate, increased thirst, or increased hunger.
Once a diagnosis of type 1 diabetes is confirmed, the patient is followed closely both to monitor response to treatment as well as to recognize and mitigate complications arising from diabetes. Routine diabetes checkups as well as annual physical exams provide an opportunity to examine the patient for the development of these complications. Further, patients diagnosed with type 1 diabetes are surveyed for the presence of existing conditions or comorbidities that may worsen in the presence of diabetes (such as hypertension).
The hallmark symptom of diabetes is hyperglycemia. However, hyperglycemia is a symptom of both type 1 and type 2 diabetes and therefore cannot be used to aid in the differentiation of these conditions. In addition to hyperglycemia, the most common symptoms of type 1 diabetes are polyuria, polydipsia, and polyphagia (Hussain, 2010).
Blood glucose tests are used for the definitive diagnosis of diabetes. Three blood glucose tests have been developed for use in this setting. While these tests may be used to diagnose diabetes, they cannot by themselves differentiate type 1 diabetes (NIDDK, 2010a).
The fasting plasma glucose (FPG) test is a measure of the blood glucose levels in an individual following a period of fasting. This method assesses the ability of the body to properly store glucose following a meal. It is performed after the patient has not eaten for a period of at least 8 hours and is most reliable when done in the morning.
In the FPG test, normal levels of blood glucose are considered to be ≤99 mg/dL, while levels between 100 and 125 mg/dL are considered to be prediabetic. Blood glucose levels of ≥126 mg/dL are defined as diabetic and must be confirmed by repeating the FPG test on a different day.
The FPG test is convenient and low cost and is therefore the preferred blood glucose test for the diagnosis of diabetes. However, it may miss some cases of diabetes that would be recognized using other blood glucose tests.
|Plasma Glucose Level (mg/dL)||Diagnosis|
|* Confirmed by repeating the test on a different day.
Source: NIDDK, 2010a.
The oral glucose tolerance test (OGTT) measures blood glucose levels in an individual who has fasted for a period of at least 8 hours and is administered 2 hours after that person has consumed a glucose-containing liquid. This method assesses the ability of the body to tolerate an influx of glucose. Generally, the liquid is composed of 75 grams of glucose dissolved in water.
Using the OGTT test, blood glucose levels of ≤139 g/dL are considered normal, between 140 to 199 mg/dL are prediabetic, and ≥200 g/dL are diagnostic of diabetes. As with the FPG test, a positive diagnosis of diabetes using the OGTT must be repeated on a different day for confirmation.
Although less convenient than the FPG test, the OGTT test has been shown to be more sensitive and therefore more reliable.
|2-Hour Plasma Glucose Level (mg/dL)||Diagnosis|
|* Confirmed by repeating the test on a different day.
Source: NIDDK, 2010a.
A random plasma glucose test is an informal measure of the blood glucose level. This method is performed at random, with no fasting requirement. Using this test, a blood glucose level of ≥200 mg/dL in the presence of other symptoms may indicate that a patient has diabetes. In the case of a positive random plasma glucose test, a diagnosis of diabetes is confirmed using either an FPG or OGTT.
Once diabetes has been diagnosed, it is necessary to establish whether the patient has type 1 or type 2 diabetes in order to determine the proper course of treatment (Hussain, 2010).
There is no definitive cure for type 1 diabetes. Instead, it is a chronic and lifelong condition that requires patients to adhere to a prescribed diet and therapeutic regimen. With faithful adherence, patients with type 1 diabetes may live a long life and experience less frequent and less severe diabetes-related complications. The lifelong commitment these patients must make includes frequent monitoring of blood glucose levels, taking regular doses of insulin, following a diet designed to manage blood sugar levels, and participating in an active exercise routine.
The most effective management of type 1 diabetes occurs when a multidisciplinary team approach is taken. The multidisciplinary team may include primary care providers, nurses, endocrinologists, registered dietitians, and diabetes educators. Development of diabetes-related complications may also necessitate additional specialists, such as cardiologists, ophthalmologists, dermatologists, and podiatrists, among others. A pediatrician is a crucial member of the care team in the case of juvenile patients with type 1 diabetes.
Patients with type 1 diabetes must also commit to regular doctor visits to be sure that their disease is properly controlled. The two primary goals of therapy for type 1 diabetes are to reduce the frequency and severity of symptoms and to prevent the development of diabetes-related complications. Notably, patients who are able to maintain well-managed glucose levels experience fewer and less severe diabetes-related complications.
PRIMARY GOALS OF THERAPY
Diet is one of the first and major steps addressed when developing a strategy to manage type 1 diabetes. Contrary to general belief, there is not a “diabetic diet.” Instead, patients are encouraged to maintain healthy eating habits, choosing foods that are high in nutritional value but low in fat and calories. Additionally, the patient’s eating habits and lifestyle should be taken into consideration when designing a diet for type 1 diabetics (Mayo, 2009; NIDDK, 2010a).
Patient education is an important component in implementing a diet plan. To gain the most from their diet plan, patients need to understand the importance of timing, meal size, and meal frequency in addition to what foods their meals should include.
Patients with type 1 diabetes often require frequent food intake in combination with insulin therapy in order to maintain normal blood glucose levels. (Source: NIDDK, 2010a.)
A dietitian can help patients learn how to count the amount of carbohydrates they consume in a meal. This is necessary to calculate the proper amount of insulin to administer in order to metabolize the carbohydrates and maintain normal blood glucose levels.
A comprehensive diet plan should be designed for patients with type 1 diabetes. This plan should include a recommended daily caloric intake as well as guidance for how these calories should be divided throughout the day. For example, one recommended distribution consists of 20% of calories consumed at breakfast, 35% consumed at lunch, 30% consume at dinner, and 15% consumed in a late-evening snack. However, smaller, more frequent meals throughout the day may be needed for patients who experience hypoglycemia.
Additionally, a dietitian can help to recommend the amount of fats and proteins that should be consumed. The amount of these nutrients may be individualized depending on the needs of the patient; for example, reduced protein intake is indicated in the case of a patient with a complication such as nephropathy. Because patients with type 1 diabetes are at an increased risk for cardiovascular complications, a diet low in cholesterol is also recommended.
In addition to diet, exercise is one of the cornerstones of a comprehensive program for the management of type 1 diabetes. Patients should therefore be encouraged to maintain a regular exercise routine, typically lasting for 30 minutes 3 to 5 times per week (NIDDK, 2010a).
RECOMMENDED PHYSICAL ACTIVITIES
Because exercise can dramatically affect blood glucose levels, patients should be cautioned to take action to prevent hypoglycemia, or a drop in blood glucose. For example, patients may decrease the amount of insulin administered by 10% to 20%, or increase their blood glucose level by eating a small snack. Patients can be educated to check their blood glucose levels more often when first beginning an exercise regimen in order to determine how that physical activity will affect their blood glucose levels.
It is important for patients with type 1 diabetes to maintain normal blood glucose levels. Achieving and maintaining glycemic control is associated with reductions in the frequency and severity of diabetes-related complications.
Patients with type 1 diabetes should frequently monitor their blood glucose levels, as this can be used to determine whether their disease is being properly treated. Computerized blood glucose meters provide the most accurate and precise measure of the amount of glucose circulating within the blood at a particular time. Because improper use of these meters is the primary cause of their inaccuracy, patients must be educated on how to use them.
In conditions of hyperglycemia, excess glucose enters the red blood cells circulating throughout the blood. Red blood cells also contain hemoglobin, the protein responsible for oxygen transport within the blood. When glucose enters the red blood cell, it links to the hemoglobin protein molecules, forming glycosylated hemoglobin (HbA1C). As glucose levels increase, the amount of glycosylated hemoglobin also increases.
The HbA1C, or glycosylated hemoglobin, test is a measure of the percentage of hemoglobin molecules that have glucose molecules attached. The HbA1C level is reflective of the average blood glucose level in an individual over the previous two to three months. Therefore, it is considered a long-term assessment of glucose control. The HbA1C test can help to manage type 1 diabetes by confirming blood glucose self-tests and to judge if a treatment plan is effective. Although the HbA1C test is useful for monitoring the long-term control of blood glucose levels in a patient with type 1 diabetes, it is not typically used to diagnose the disease.
HbA1C levels less than 6% are considered normal. The American Diabetes Association recommends that patients with type 1 diabetes should have a goal of achieving HbA1C levels of less than 7% in order to reduce the risk of developing diabetes-related complications.
The estimated average glucose (eAG) is a new method for understanding the management of diabetes. eAG is determined by converting the HbA1C percentage to mg/dL units. Because these units are the same as those used on blood glucose meters, they are considered to be more familiar to patients with diabetes. Therefore, providing the HbA1C percentage in these units may help patients to better understand how effectively their type 1 diabetes is being controlled (ADA, 2010).
Because type 1 diabetes is a disease caused by a loss of the ability to produce insulin, the primary treatment is insulin therapy. In addition, other medications may be prescribed to work in conjunction with insulin in an effort to reduce hyperglycemia. Patients who develop diabetes-related complications often require medication specific to their complication. For example, patients with cardiac complications may be treated with low-dose aspirin therapy, cholesterol-lowering drugs, or high blood pressure medications.
In adults, the initial daily dose of insulin is calculated based on the weight of the patient. Because it is quickly degraded, insulin must be administered throughout the day to maintain steady levels. It is generally divided so that 50% of the total daily dosage is administered before breakfast, 25% before dinner, and the remaining 25% prior to going to sleep.
Once an initial dose is determined by the physician, the patient can learn how to adjust the amount and timing of insulin administered based on measured blood glucose levels. Typically, the dosage of insulin is adjusted 10% at a time, and the effects of each adjustment are monitored over a short time period (3 days) before making further changes. Overall, the patient should adjust their insulin to achieve a preprandial (before a meal) blood glucose level between 80 and 150 mg/dL (Votey, 2009).
Several different types and formulations of human insulin are available to treat type 1 diabetes. An inhaled formulation of insulin was previously available but discontinued in 2007 due to too little use by patients. Oral administration of insulin is not possible, because the enzymes in the stomach create too harsh an environment and lead to insulin degradation. Therefore, the only currently available options for insulin therapy are subcutaneous injection or intravenous administration. Subcutaneously injected insulin is the first-line therapy. Insulin injections are self-administered using either a needle and syringe or an insulin pen—a device that resembles an ink pen, with the “ink” cartridge instead filled with insulin.
Insulin may also be administered via a battery-operated infusion pump. Generally, this method is used to subcutaneously deliver a continuous amount of rapid-acting insulin through a catheter. The steady-state amount of insulin that results is referred to as the patient’s “basal level.” Prior to each meal, the patient must still test their blood glucose level and self-inject additional insulin as needed. This method allows better control of blood glucose levels than relying only on self-injecting insulin multiple times per day.
All insulin available in the United States is synthetic human insulin manufactured in a laboratory. However, some patients find their diabetes is better managed using animal insulin, and therefore the Food and Drug Administration (FDA) permits it to be imported for personal use (ADA, 2010). Animal-derived insulins were previously manufactured in the United States, but they were found to be antigenic, causing an immune reaction.
Types of insulin are categorized based upon their time of onset, peak, and duration of action. They are further classified as long-acting, intermediate-acting, and rapid-acting.
|Rapid-acting||Regular insulin||0.5–1 hour||2.5–5 hours||6–8 hours|
|Lispro insulin||15 minutes||1–3 hours||1–5 hours|
|Aspart insulin||15 minutes||1–3 hours||1–5 hours|
|Intermediate-acting||Neutral protamine Hagedorn (NPH)||1–1.5 hours||4–12 hours||Up to 24 hours|
|Long-acting||Ultralente insulin||4–8 hours||16–18 hours||Over 32 hours|
|Insulin glargine||4–8 hours||16–18 hours||24 hours|
Insulin therapy regimens for patients with type 1 diabetes frequently combine insulin types, offering patients the ability to benefit from each class. This is commonly done by drawing calculated doses of two insulin types into the same syringe, allowing for a single injection. This method should only be done immediately before administering the insulin injection. Premixed insulin preparations are also available, but their fixed ratios of each insulin type may limit their use.
Rapid-acting insulins include regular insulin, lispro insulin, and aspart insulin. These are the only available insulins that can be administered intravenously. Because of their rapid onset of action, they can be used when quick control of blood glucose levels is needed, such as before a meal. A rapid influx of insulin stimulates glucose-uptake and storage, thus reducing blood sugar.
Regular, or traditional, insulin is a formulation of zinc insulin crystals suspended in solution. The onset of action for traditional insulin is between 0.5 to 1 hour, with a peak activity between 2.5 and 5 hours following administration. The duration of activity of regular insulin is 6 to 8 hours. The other rapid-acting insulins are genetically engineered versions of regular insulin in which specific amino acid substitutions have been made. Lispro insulin contains a reversal of the amino acids lysine and proline, while aspart insulin contains an aspartic acid substitution for proline. Each of these modifications has the result of allowing more rapid insulin absorption and activity, with a rapid onset (up to 15 minutes), peak activity (1 to 3 hours), and duration (between 1 to 5 hours) of action. These quicker responses allow the patient greater flexibility in administration, with the possibility of their administration immediately before eating.
Intermediate-acting insulins have a slower onset of action compared to rapid-acting formulations but have a characteristically longer duration of action. Thus, they are often administered in combination with rapid-acting formulations, which maximizes the benefit of both insulin types. Additionally, intermediate-acting insulin formulations are often used at bedtime in order to provide needed insulin throughout the night. Neutral protamine Hagedorn (NPH) is a suspension of zinc insulin crystals combined with protamine, a positively charged amino acid polypeptide. The onset of action of this class of insulins is between 1 and 1.5 hours, with a peak effect occurring in 4 to 12 hours. The greatest benefit of intermediate-acting insulins is their long duration of activity, up to 24 hours.
Long-acting insulins, as their name suggests, have a very long duration of action. This insulin class is generally combined with rapid-acting insulin, offering patients an improved and steadier control of their insulin and blood glucose levels. Long-acting formulations are often administered in the morning in order to provide all-day insulin coverage. The pharmacology of long-acting insulin is similar to that of the natural insulin normally secreted by the pancreas. These insulins are generally administered once daily.
There are two main types of long-acting insulins. The first, ultralente insulin, is a formulation of zinc insulin crystals in suspension. Compared to other formulations, the zinc insulin crystals in ultralente insulin are larger and therefore break down at a slower rate. Ultralente insulin has an onset of action between 4 and 8 hours, a peak effect at 16 to 18 hours, and a duration of action lasting over 32 hours.
Insulin glargine is a newer type of long-acting insulin that has similar characteristics to ultralente insulin, with the exception of a slightly shorter duration of action (24 hours). Unlike other insulin types, insulin glargine should not be mixed with other insulin types in the same syringe for single administration. Recently published observational clinical studies have reported a possible association of insulin glargine with cancer (FDA, 2009). The data within these studies must be carefully compared and interpreted, as they are inconsistent between studies, derived from patient populations with different baseline characteristics, and generated from studies that may be too short to allow this conclusion to be made. The American Diabetes Association cautions against overreacting to these reports.
Amylin is a small hormone that is normally secreted by pancreatic beta cells in conjunction with insulin. Once it enters the blood circulation, amylin contributes to glycemic control by delaying gastric emptying, decreasing blood glucose release following a meal, and modulating appetite. These mechanisms allow amylin to work synergistically with insulin to keep blood glucose levels normal (Votey, 2009).
A synthetic version of amylin, pramlintide, is available. Pramlintide is currently approved for use in adult patients with type 1 diabetes who are unable to achieve a desired glucose level despite optimal insulin therapy. It is subcutaneously administered prior to a meal. Initially started at a low dose (15 mcg), if the patient does not experience significant nausea, the pramlintide dosage is gradually titrated upward in 15 mcg increments to a final maintenance dosage between 30 and 60 mcg per dose. When initiating pramlintide, the patient should decrease their normal insulin dosage. Once the final pramlintide dose has been determined, the patient can then adjust their insulin dosage to optimize blood glucose control.
Hyperglycemia, the hallmark symptom of diabetes, occurs when an individual experiences high levels of blood glucose. Nearly all patients with type 1 diabetes experience hyperglycemia during the course of their disease (NIDDK, 2010a).
In patients who are being treated for type 1 diabetes, the onset of hyperglycemia may be indicative of poor disease management. This may occur as a result of a skipped or forgotten dose of insulin, too low a dosage of insulin, eating too much food, or eating foods that add too much sugar to the diet. Other causes of hyperglycemia in patients with type 1 diabetes include infection, illness (such as a cold or flu), increased stress, or decreased physical activity.
SYMPTOMS OF HYPERGLYCEMIA
If they suspect that they are experiencing an episode of hyperglycemia, patients with type 1 diabetes should immediately test their blood glucose level. Additionally, type 1 diabetics whose blood glucose level is higher than 240 mg/dL should also test for the presence of ketones in their urine.
Often, blood glucose levels may be lowered simply by exercising. However, patients who have ketones in their urine should not exercise, because exercising when ketones are present can actually increase blood glucose levels. Hyperglycemia lasting over several days may require more thorough intervention, such as altering a diet plan. If neither exercise nor diet changes are effective to treat hyperglycemia, altering the schedule or dosage of insulin may be necessary.
One of the major impacts of type 1 diabetes is the potential for the development of complications of the disease. These complications may be classified as either acute or chronic.
Acute complications are emergency conditions that can become life-threatening if not immediately treated. The two main acute complications that affect patients with type 1 diabetes are diabetic ketoacidosis and hypoglycemia.
Diabetic ketoacidosis (DKA) is a serious acute complication that may lead to diabetic coma and, if not treated, death. Although DKA may occur in anyone with diabetes, it is far more common in patients with type 1 diabetes compared to those with type 2 diabetes (ADA, 2010; Trachtenbarg, 2005).
This condition occurs when insufficient insulin levels cause the body to break down fats instead of glucose for energy. DKA may occur if the patient does not adhere to their prescribed insulin therapy or if the insulin regimen is not properly tailored to the patient’s needs. Alternatively, the condition may be triggered by a stress, injury, or illness that alters the balance of insulin and glucose.
COMMON CAUSES OF DKA
The primary evidence that DKA is occurring is the presence of ketones in the urine. Acidic ketones, a byproduct of fat metabolism, become toxic when they accumulate in the blood. Their toxicity is due to their ability to cause acidosis, a drop in blood pH. Normally, the pH of blood is tightly regulated between 7.38 and 7.44; the build-up of ketones in the blood causes the pH to drop to below 7.3. The severity of DKA can be established with a standard laboratory work-up and is primarily determined by the blood pH level and bicarbonate level, in combination with the patient’s mental status.
The onset of DKA may occur in less than 24 hours. Once toxicity has reached a threshold and symptoms begin to occur, DKA quickly develops into a life-threatening condition in only a few hours. Very early signs of DKA result from hyperglycemia and therefore include thirst, dry mouth, frequent urination, and high blood glucose levels. These signs are followed by other symptoms, often beginning in the gastrointestinal system, such as nausea, vomiting, and abdominal pain. Another symptom of DKA is known as Kussmaul breathing (also referred to as air hunger), resulting from difficulty breathing. Patients also feel constantly tired, have dry or flushed skin, and appear confused. A fruity odor may be apparent in their breath.
SYMPTOMS OF DKA
Elevated levels of ketones are an important sign that a patient’s blood glucose levels are not properly regulated. The presence of ketones can be tested using a simple urine test strip. Because early signs of DKA may be slow to develop, it is recommended that patients with type 1 diabetes should test for ketones in their urine if their blood glucose levels reach over 250 mg/dL. Additionally, because DKA is more likely to occur when diabetic patients have an illness, a urine test should be performed every four to six hours to check for ketones.
The patients should be educated to contact their health care provider for guidance if a urine test reveals an accumulation of ketones. Patients should also be warned to not exercise if they experience elevated ketone levels.
Most patients require hospitalization for treatment of DKA. While patients with mild DKA may be treated at home under observation, the guidelines for patients to be admitted to the hospital for therapy include blood glucose levels over 250 mg/dL, an arterial blood pH level below 7.3, a serum bicarbonate level of less than 15 mEq/L, and moderate to high levels of ketones present in their urine. The treatment priorities for a patient with DKA include protection and maintenance of the airway and treatment for shock, if present. If the underlying cause of DKA is an infection or illness, the patient should be treated for these as well.
Currently, the standard of care for patients with DKA includes an intravenous insulin drip. Additionally, the patient is administered fluids and electrolytes, especially to restore potassium balance. Once a patient is stabilized and they prepare to return home, they should be educated to prevent the recurrence of DKA. The importance of properly adhering to their insulin regimen should be stressed, especially if poor adherence precipitated the DKA episode. Additionally, the patient should be advised to carefully monitor their blood glucose levels and to check for the presence of ketones in their urine if their blood glucose levels become elevated. Finally, they should be advised to schedule and attend regular check-ups so that their condition may be monitored by their physician.
Hypoglycemia, or low blood glucose levels, is a serious side effect that can occur in patients with type 1 diabetes. Normally, decreased blood glucose levels trigger the pancreatic hormone glucagon to activate the breakdown of glycogen within cells, causing the release of glucose into the bloodstream. This results in restoration of normal blood glucose levels. However, this response is impaired in patients with type 1 diabetes, whose disease is controlled by insulin therapy. Because of their lifelong dependence on insulin treatment, patients with type 1 diabetes have an increased likelihood of experiencing hypoglycemia compared to patients with type 2 diabetes (NIDDK, 2010a).
Hypoglycemia may occur when patients with type 1 diabetes take a dose of insulin but then miss a meal, have a strenuous exercise workout, or for some reason deplete their blood glucose. It is sometimes referred to as an “insulin reaction.” Consumption of alcoholic beverages may also cause hypoglycemia in type 1 diabetics. In addition to insulin therapy itself, medications that induce or increase insulin production may cause hypoglycemia; however, because of their inability to produce their own insulin, this is not an important cause of hypoglycemia in patients with type 1 diabetes. Conversely, the injectable medication pramlintide, which is administered in conjunction with insulin to patients with type 1 diabetes, is associated with a risk of hypoglycemia.
Short or mild cases of hypoglycemia can cause weakness and fatigue. Prolonged or serious cases are more dangerous, causing confusion, clumsiness, or unconsciousness. Especially severe cases may lead to irreversible brain damage, seizures, comas, and ultimately death.
Hypoglycemia can have a very sudden onset, and early symptoms may appear to be mild. Patients with type 1 diabetes should be made aware of the danger associated with hypoglycemia and educated to recognize its symptoms so that they can intervene before the condition becomes serious.
SYMPTOMS OF HYPOGLYCEMIA
Because a normal night’s sleep means that patients experience a prolonged period without a meal, type 1 diabetes patients should also be informed that hypoglycemia may occur during sleep. It is important to occasionally monitor blood glucose levels during the night to determine whether they become too low.
SIGNS OF HYPOGLYCEMIA DURING SLEEP
When patients recognize the onset of hypoglycemic symptoms, they should immediately check their blood glucose levels. Levels below 70 mg/dL require immediate intervention. A variety of “quick-fix” sugar-filled foods provide a simple and quick means to raise blood glucose levels.
QUICK-FIX FOODS TO TREAT HYPOGLYCEMIA
Listed amounts are for adults and may be decreased for small children.
Once patients consume one of these quick-fix foods, they should recheck their blood glucose level 15 minutes later to be sure it has been raised to 70 mg/dL or above. If not, they should consume another serving of one of these sugar-containing foods. Either way, this quick-fix intervention should be followed by a snack or meal within one hour. Because of their propensity to develop hypoglycemia, patients with type 1 diabetes should be instructed to always have one of these quick-fix interventions available to them.
Because cases of moderate to severe hypoglycemia can cause patients to lose consciousness or otherwise be unable to help themselves, they should wear a medical identification bracelet or a medical alert tag. A family member, coworker, or care provider can be trained to give an injection of glucagon, which causes blood glucose levels to be rapidly restored to normal.
Frequent episodes of hypoglycemia may be a sign that the patient’s blood glucose levels are not being effectively managed. These patients could benefit from a different meal plan, a new insulin administration schedule, or a modified physical exercise routine.
Patients with type 1 diabetes are at an increased risk to develop hypoglycemia and therefore should be educated in strategies to prevent and treat the condition. For example, these individuals can be taught to learn what causes hypoglycemia and recognize events in their lives that trigger low blood glucose levels. Frequent monitoring of blood glucose levels can help to catch early or prevent hypoglycemia; this is particularly important before undertaking an activity such as exercising or driving. In the event hypoglycemia occurs, patients should be taught to always have several servings of quick-fix foods available to them in order to prevent it from worsening. Other strategies include wearing a medical alert bracelet and discussing how to handle a hypoglycemic emergency with friends, family, or coworkers.
Chronic complications may also be serious or life-threatening but generally become more serious over an extended period of time. Chronic complications typically develop from damage caused by continual or frequent hyperglycemia. One of the most important interventions to prevent the frequency and severity of chronic complications resulting from type 1 diabetes is to maintain blood glucose levels to as close to normal as possible. This long-term therapeutic goal is a commitment for the patient. Because theirs is a chronic disease, patients have a lifelong increased risk for these complications. If a patient does develop a disease complication, early recognition and intervention are critical to prevent a worsening of disease.
Patients with type 1 diabetes have an increased risk for a number of cardiovascular complications, including heart disease, stroke, and hypertension. The primary cause of cardiovascular complications in diabetics is increased atherosclerosis. Atherosclerotic plaques have a propensity to form in diabetic patients as a result of three major mechanisms: 1) the glycosylation (addition of a sugar molecule) of proteins and lipids within the arterial wall; 2) oxidative stress; and 3) activation of the enzyme protein kinase C, which leads to the expression of growth factors that induce the thickening of the arterial wall (ADA, 2010; Aronson, 2002).
Atherosclerosis occurs as a result of the build-up of fatty material deposits on the arterial wall. As these deposits accumulate, the vessel narrows, reducing and eventually impairing blood flow. (Source: National Heart, Lung, and Blood Institute, 2009.)
Because of the seriousness of cardiovascular complications, patients with type 1 diabetes should receive regular screening for signs, symptoms, and risk factors of cardiac disease. These individuals should also be assessed for other risk factors of cardiac disease, as this may heighten their already greater risk to develop this complication. A cardiac stress test is indicated for patients in whom cardiovascular complications are suspected. In addition, patients should be educated to watch for warning signs of cardiovascular disease and stroke.
OTHER RISK FACTORS FOR CARDIOVASCULAR CONDITIONS
If the patient experiences warning signs of a stroke, they should contact emergency personnel immediately. If a stroke is suspected, several tests will be performed. The patient should be examined for changes in body function such as the ability to move their arms and legs, to read, or to describe an image. Computed tomography (CT) scans or magnetic resonance imaging (MRI) may be used to image the brain, looking for signs of blood vessel damage. Additionally, a cerebral arteriogram may be used to determine if the arteries leading to the brain are narrowed or blocked; in this exam a dye is injected into a catheter that is positioned in an artery in the neck.
WARNING SIGNS OF A STROKE
Immediate intervention is critical to reduce the damage caused by a stroke. “Clot-busting” drugs are used to help dissolve clots blocking blood flow from the heart to the brain. However, these drugs are only useful if given promptly (within three hours) after the first symptoms of a stroke appear. Therefore, it is important that type 1 diabetic patients, as well as their families, coworkers, and friends, be taught to recognize the warning signs of a stroke.
Hypertension, or high blood pressure, is another serious cardiovascular complication that may develop in patients with type 1 diabetes. Because hypertension can add to the already present risk of stroke, cardiac disease, and other complications in diabetic patients, the American Diabetes Association and the National Institutes of Health recommend a lower blood pressure target (130/80 mmHg) in individuals with diabetes compared with the general public.
Hypertension can occur without warning, and many patients do not realize their blood pressure is elevated. Therefore, patients with type 1 diabetes should have their blood pressure monitored regularly at every office visit. If hypertension is discovered, lifestyle interventions should be recommended to help lower the blood pressure. These can include an improved diet, weight loss, exercise, and limiting alcohol consumption and smoking.
In addition to lifestyle changes, blood pressure–lowering medications may be prescribed. The type and amount of the medication will depend on the specific needs of each individual patient. It is important to recognize that some medications used to lower blood pressure may actually raise blood glucose levels and are therefore not appropriate for diabetic patients. The best class of blood pressure drugs for patients with diabetes is ACE inhibitors.
|Angiotensin-converting enzyme (ACE) inhibitors||Prevent the formation of angiotensin, leading to blood vessel relaxation|
|Angiotensin II receptor blockers (ARBs)||Prevent the activity of angiotensin, resulting in blood vessel relaxation|
|Beta blockers||Relax the heart by causing it to beat slower and less forcefully|
|Calcium channel blockers||Decrease the force of contraction of the heart|
|Diuretics||Help to eliminate extra body fluids|
Diabetic neuropathy is one of the most frequent complications experienced by patients with type 1 diabetes. Patients may experience a condition known as peripheral neuropathy (also referred to as distal symmetrical polyneuropathy), which is frequently manifested as a tingling sensation or the feeling of numbness in the toes. These sensations gradually travel upwards through the feet, ankles, and lower legs.
As the condition progresses, other extremities begin to be affected, such as the fingers and hands. Notably, these sensations are distributed symmetrically and therefore affect both feet and both hands, resulting in a “glove and stocking” sensation. As the condition worsens and the nerve endings in these extremities become progressively more damaged, the patient begins to lose feeling and experiences a loss of muscle control in these areas (ADA, 2010; NIDDK, 2010a).
SYMPTOMS OF PERIPHERAL NEUROPATHY
Because peripheral neuropathy is a common complication for diabetic patients, it should be screened for at each doctor’s visit. A tuning fork can be used to test the patient’s sensory ability in the hands and feet, while testing the Achilles tendon reflexes can monitor sensation in the ankles.
|Causes pain or numbness in the extremities, including the toes, feet, legs, hands, and arms|
|Autonomic||Causes changes in digestion, function of the bowel and bladder, sexual response, perspiration; may also be responsible for a condition known as hypoglycemia unawareness, in which a patient no longer experiences warning symptoms of low blood glucose levels|
|Proximal||Causes pain in the thighs, hips, or buttocks|
|Focal||Causes a sudden weakness of a nerve or group of nerves (any nerve in the body), causing weakness or pain|
Foot complications arising from peripheral neuropathy are common among patients with type 1 diabetes. Nerve damage can cause numbness and a loss of feeling in the feet, and therefore patients with these symptoms are more prone to be unaware of foot discomfort (such as a pebble in the shoe causing a blister) until the damage is already done. Nerve damage also reduces the oil and moisture that is normally supplied to the skin of the foot, causing it to peel, crack, and become very dry.
Neuropathy is not the sole cause of foot complications in patients with type 1 diabetes. Poor blood circulation in the feet occurs in diabetic patients due to hyperglycemia-induced narrowing and hardening of the blood vessels. Patients with poor blood circulation in their feet may constantly feel that their feet are cold; however, they should use caution when attempting to warm their feet, as neuropathy-induced loss of feeling may reduce their ability to realize whether their foot is being burned by water or a heating pad that is too warm.
Poor blood circulation may also cause a build-up of pressure within the foot, causing calluses that can break down and turn into open sores. These foot ulcers, which occur most often on high-pressure areas such as the ball of the foot or the underside of the big toe, are a common cause of foot infections in diabetic patients. If the ulcer becomes infected, the problem may be compounded by poor blood circulation in the foot.
Together, foot complications may ultimately cause the patient to be forced to undergo amputation. In order to prevent amputation, patients should be counseled to maintain appropriate foot care, which may include special therapeutic shoes, cleaning and removal of calluses and foot ulcers, and exercise. Patients should also be encouraged to stop smoking, as smoking contributes to poor blood circulation and the progression of foot complications.
Patients with type 1 diabetes have a high risk for the development of kidney disease, also referred to as nephropathy. Kidney disease occurs due to high blood glucose levels, causing the organs to filter too high a volume of blood. This increased volume causes the kidneys to become overworked, leading to their inability to keep protein from being filtered out of the blood. As a consequence, protein that would otherwise be useful to the body is filtered into the urine and excreted. The presence of a small amount of protein in the urine is called microalbuminuria. When kidney disease has progressed to later stages and higher levels of protein are present in the urine, this condition is known as macroalbuminuria (ADA, 2010).
Damaged kidneys allow protein to be filtered out of the blood and excreted in the urine. (Source: National Diabetes Information Clearinghouse, 2008.)
Early intervention is a key step to limiting kidney damage. Tight control of blood glucose levels can help to reduce the risk of microalbuminuria by approximately one-third (ADA, 2010). Several treatments are also available to slow kidney disease when it is caught in the microalbuminuria stage. Once microalbuminuria develops, tight control of blood glucose levels can reduce the risk of progressing to macroalbuminuria by nearly half (ADA, 2010). However, once the disease reaches the macroalbuminuria stage, it has progressed to advanced stages and is usually followed by the development of end-stage renal disease (ESRD), which leads to kidney failure.
Because the kidney overworks itself in order to compensate for its decreased efficiency, early stages of kidney disease are often not accompanied by symptoms. Therefore, careful monitoring for signs of kidney deficiency at routine check-ups is an important component of care for patients with type 1 diabetes. In addition to a urine test to monitor the presence of proteins, a blood test can be performed to check for the presence of waste products. It is not until the disease has progressed that the first symptoms may become noticeable. While these may vary from patient to patient, they often begin with fluid build-up. Other symptoms of kidney disease are listed below.
SYMPTOMS OF NEPHROPATHY
Slight elevations in blood pressure can have a dramatic effect on kidney disease progression; therefore, patients should be counseled to keep their blood pressure levels low. This is preferably done by changes in lifestyle, such as losing weight, decreasing salt intake, avoiding alcohol and tobacco use, and increasing exercise. However, if these methods do not lower the blood pressure levels enough, medications may be used.
Another method to control the progression of kidney disease is to limit the amount of protein in the diet. Because proteins contribute to the work the kidney must do, reducing dietary protein can decrease the workload of the organ. However, a patient should only begin a low-protein diet under the care of a physician and with the guidance of a nutritionist.
At end-stage renal disease, kidney function is so limited that the patient requires kidney dialysis in order to achieve adequate removal of toxins from the blood. Patients with ESRD who do not have heart or blood vessel disease may qualify for kidney transplantation. Despite the significant risks associated with this procedure, patient survival is dramatically improved with transplantation compared with dialysis. While only 1/3 of patients on kidney dialysis are still alive after 5 years, the 5-year survival of patients who receive a kidney transplant is 75%, increasing to 83% if the donated kidney is from a living relative (ADA, 2010).
High blood glucose levels in patients with type 1 diabetes lead to an increased risk of eye complications. Although some of these complications may lead to blindness, many are only minor eye problems. Diabetic retinopathy, the general term used to refer to disorders of the retina that are caused by diabetes, is categorized as two major types (ADA, 2010):
Retina damage results primarily from swelling and weakening of the blood vessels. (Source: National Diabetes Information Clearinghouse, 2008.)
Early diagnosis of diabetic retinopathy is the key factor in the ability of treatments to limit the resulting vision loss. Because of this, patients with type 1 diabetes should be counseled to have a yearly eye exam in which the eye is dilated and examined for evidence of retinopathy.
Photocoagulation is a type of treatment in which a laser is used to produce tiny burns on the retina. These burns seal leaky capillaries, reducing the build-up of blood behind the eye. Although photocoagulation is quite effective when implemented when vision is still normal, it does not work when the retina has already become detached or when a lot of bleeding has occurred. In these cases, the remaining treatment option is a vitrectomy, a surgical resection of the scar tissue and cloudy fluid inside the eye. A vitrectomy is most effective when done prior to retinal detachment.
Diabetic patients are 40% more likely than individuals without diabetes to develop glaucoma (ADA, 2010). Glaucoma occurs when pressure that builds up in the eye pinches the vessels that supply blood to the retina and optic nerve. The decrease in blood supply damages the retina and optic nerve, leading to loss of vision. Patients with diabetes are 60% more likely than those without diabetes to develop cataracts. This clouding of the eye lens also occurs at younger ages in diabetic patients (ADA, 2010).
SYMPTOMS OF EYE COMPLICATIONS
Type 1 diabetes is a serious disease, the chronic nature of which requires a lifelong commitment to therapy. Unlike type 2 diabetes, type 1 diabetes is caused by an autoimmune reaction, the results of which cause the body to be unable to properly store and process blood glucose. The hallmark characteristic of type 1 diabetes is hyperglycemia. Symptoms of hyperglycemia include increased thirst, blurred vision, frequent urination, and increased hunger.
While there are many strategies to manage type 1 diabetes, such as exercise and diet, the primary treatment is insulin therapy to make up for the lack of insulin production in these patients. Insulin administration allows patients to normalize their blood glucose levels. Tight control of blood glucose is an essential step to prevent the development and/or worsening of diabetes-related complications, a common occurrence in these patients.
The long-term therapy of patients with type 1 diabetes is best managed by a multidisciplinary care team, comprised of primary care providers, nurses, endocrinologists, and other specialists (i.e., cardiologists, ophthalmologists, dermatologists, and podiatrists), registered dietitians, and diabetes educators. Although there is currently no cure, with continued care and oversight as well as careful and committed adherence to lifestyle changes and treatments, patients with type 1 diabetes may experience an active and full life.
American Diabetes Association: Diabetes Basics
American Diabetes Association: Living with Diabetes
Centers for Disease Control and Prevention (Diabetes public health resource)
Children with Diabetes (an online community for kids, families, and adults with diabetes)
International Diabetes Federation
Mayo Clinic: Diabetes
Medline Plus: Diabetes.
National Institutes of Health: National Diabetes Information Clearinghouse
Achenbach P, Bonifacio E, Koczwara K, and Ziegler AG. (2005). Natural history of type 1 diabetes. Diabetes, 54 (Suppl 2), S25-S31.
American Diabetes Association (ADA). (2010). Accessed January 30, 2010, at http://www.diabetes.org/.
Appel SJ, Wadas TM, Rosenthal RS, and Ovalle F. (2009). Latent autoimmune diabetes of adulthood (LADA): An often misdiagnosed type of diabetes mellitus. Journal of the American Academy of Nurse Practioners, 21(3), 156–159.
Aronson D and Rayfield EJ. (2002). Cardiovascular Diabetology, 1, 1.
Bonifacio E, Hummel M, Walter M, Schid S, Ziegler AG. (2004). IDDM1 and multiple family history of type 1 diabetes combine to identify neonates at high risk for type 1 diabetes. Diabetes Care, 27(11), 2695–2700.
Centers for Disease Control and Prevention (CDC). (2007). National diabetes fact sheet. Accessed January 30, 2010, at http://www.cdc.gov/diabetes/pubs/pdf/ndfs_2007.pdf.
Choudhuri G, Lakshmi CP, and Goel A. (2009). Pancreatic diabetes. Tropical Gastroenterology, 30(2), 71–75.
Dean L and McEntyre J. (2004). The genetic landscape of diabetes [Internet]. Bethesda: National Library of Medicine, National Center for Biotechnology Information. Accessed January 30, 2010, at http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=diabetes.
Food and Drug Administration (FDA). (2009). Early communication about safety of Lantus (insulin glargine). Accessed January 30, 2010, at http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsand
Hussain AN and Vincent MT. (2010). Diabetes mellitus, type 1. Accessed January 30, 2010, at http://emedicine.medscape.com/article/117739-overview.
Mayo Clinic. (2010.) Type 1 diabetes. Accessed January 30, 2010, at http://www.mayoclinic.com/health/type-1-diabetes/DS00329.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2010a). Diagnosis of diabetes. Accessed January 2010 at http://diabetes.niddk.nih.gov/dm/pubs/diagnosis/index.htm.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2010b). Diabetes prevention trial of type 1 diabetes (DPT-1). ClinicalTrials.gov. Identifier: NCT00004984.
Sadauskaite-Kuehne V, Ludvigsson J, Padaiga Z, Jasinskiene E, and Samuelsson U. (2004). Longer breastfeeding is an independent predictive factor against development of type 1 diabetes mellitus in childhood. Diabetes/Metabolism Research and Reviews, 20(2), 150–157.
Trachtenbarg DE. (2005). Diabetic ketoacidosis. American Family Physician, 71, 1705–1714.
Votey SR and Peters AL. (2009). Diabetes mellitus, type 1 – a review. Accessed January 30, 2010, at http://emedicine.medscape.com/article/766036-overview.
Yu L, Cuthbertson DD, Eisenbarth GS, and Krischer JP. (2002). Diabetes Prevention Trial 1: Prevalence of GAD and ICA512 (IA-2) autoantibodies by relationship to proband. Annals of the New York Academy of Sciences, 958, 254–258.
NursingCEU.com is a Wild Iris Medical Education Website
Copyright © Wild Iris Medical Education, Inc.
Forest Photograph © Jon Klein