Abbreviations/Definitions
- Ketone Bodies: any of three related compounds (acetone, acetoacetic acid, beta-hydroxybutyric acid) produced during the metabolism of fats
- DKA: Diabetic KetoAcidosis – a life-threatening condition that develops when cells in the body are unable to get the sugar (glucose) they need for energy because there is not enough insulin; when the sugar cannot get into the cells, it stays in the blood
- Pre-diabetes: a condition characterized by slightly elevated blood glucose levels, regarded as indicative that a person is at risk of progressing to Type 2 diabetes
- Incretins: a group of metabolic hormones that stimulate a decrease in blood glucose levels; they are released after eating and enhance the secretion of insulin from pancreatic beta cells by a blood glucose-dependent mechanism
Anatomy/Physiology
Describe the primary endocrine and exocrine functions of the pancreas.
The primary endocrine function of the pancreas is the production of hormones to regulate the use of body fuels, mainly glucose. The islets of Langerhans secrete insulin and glucagon directly into the blood
The primary exocrine function of the pancreas is the production of enzymes necessary for digestion. Some examples include trypsin and chymotrypsin which help metabolize protein and polypeptides, lipase which helps metabolize fat, and alpha-amylase which aids in the metabolism of starch and dextrin.
Describe the effects of glucagon, epinephrine, growth hormone, corticosteroids and somatostatin on blood glucose levels.
Glucagon is the hormone released from the alpha cells of the pancreas when blood glucose levels fall below normal. Glucagon raises blood glucose levels by stimulating glycogenolysis and gluconeogenesis. It provides additional substrate to help meet energy requirements by stimulating lipolysis.
Epinephrine is another hormone that is released when blood glucose levels fall below normal. Like glucagon, epinephrine helps to raise blood glucose levels by increasing glycogenolysis and gluconeogenesis. Additionally, it increases the secretion of glucagon from pancreatic alpha cells.
Growth hormone is secreted by the anterior pituitary gland and also helps to raise blood glucose levels when they fall below normal. It helps to raise blood glucose levels by counterbalancing the effects of insulin on muscle and fat cells (it decreases glucose uptake by these cells– glucose sparing). Because it works against the action of insulin, it is known as a “counterregulatory hormone”.
Corticosteroids are a type of medication that can result in increased blood glucose levels. There are a few ways in which corticosteroids can raise blood glucose levels. Like growth hormone, corticosteroids raise blood glucose levels by blocking the action of insulin (decreased glucose uptake by muscle and fat cells – glucose sparing), which could eventually lead to insulin resistance. They also stimulate the release of glucose from the liver into the blood.
Somatostatin is a hormone produced by the delta cells of the pancreas and lowers blood glucose levels by inhibiting the secretion of insulin, glucagon, and growth hormone.
Pathophysiology
Discuss the etiology and clinical symptoms of diabetes. Differentiate between Type 1, Type 2 and gestational diabetes.
Diabetes is caused by an inherited or acquired deficiency in the production of insulin, an ineffectiveness of the insulin produced, or both. The main clinical symptom of diabetes is hyperglycemia (elevated blood glucose levels). Chronic hyperglycemia can cause organ dysfunction and damageand eventually progress to the failure of numerous organs (e.g. eyes, kidneys, nerves, heart, blood vessels).
| Type of Diabetes | Etiology | Clinical Symptoms |
| Type 1 Diabetes – Insulin deficient | Characterized by an absolute deficiency of insulin caused by a cellular-mediated autoimmune destruction of the pancreatic beta-cells, resulting in the inability of cells to use glucose for energy. |
|
| Type 2 Diabetes – Insulin resistant | Characterized by peripheral insulin resistance with an insulin secretory defect that varies in severity. Insulin resistance is caused by a cell-receptor defect resulting in the body’s inability to use insulin. When cells can’t respond to insulin, they can’t take up glucose from the blood for fuel. Defective insulin secretory response also leads to excess production of glucose from the liver. All of this leads to elevated blood glucose levels.
Individuals with T2DM produce insulin, but their tissues are insulin resistant, which increases the need for insulin, so the pancreas increases its production and eventually the pancreas loses its ability to produce insulin. |
Many individuals will be asymptomatic for as long as 6–10 years but present with complications associated with diabetes, such as retinopathy
|
| Gestational Diabetes | During the second or third trimesters of pregnancy, metabolic alterations occur to meet maternal and fetal demands for energy and nutrients, including alterations in insulin secretion that affects glucose metabolism.
The pathophysiology of GDM is similar to T2DM, but the exact cause is unknown. It is thought that islet cell function abnormalities or peripheral insulin resistance decrease insulin secretory response and insulin sensitivity. The inability of the beta-cells to meet increased insulin needs during pregnancy results in higher levels of circulating glucose. |
|
For each of the following laboratory tests, identify normal values for healthy individuals and the significance of abnormal values in individuals with diabetes.
| Laboratory Test | Normal Values | Significance of Abnormal Values in Individuals with Diabetes |
| Fasting Blood Glucose | <100 mg/dL | Prediabetes: 100 – 125 mg/dL
Diabetes: > 126 mg/dL
|
| Two-Hour Post Prandial Blood Glucose | < 140 mg/dL | Prediabetes: 140 – 199 mg/dL
Diabetes: > 200 mg/dL |
| Serum Triglycerides | < 150 mg/dL | Borderline: > 150 – 199 mg/dL
High: > 200 – 499 mg/dL Very High: > 500 mg/dL
|
| Urinary Glucose | 0 – 0.8 mmol/L | Elevated levels may be indicative of diabetes, pregnancy, or renal glycosuria |
| Urinary Ketone Bodies | < 0.6 mmol/L |
|
| Hemoglobin A1C | < 5.7% | Prediabetes: 5.7 – 6.4%
Diabetes: > 6.5%
|
Discuss the etiology, symptoms and treatment of hypoglycemia.
Hypoglycemia is an abnormally low blood glucose level. It occurs when glucose is utilized too rapidly, glucose release rate falls behind tissue demands, or excess insulin enters the bloodstream.
Etiology of reactive hypoglycemia in individuals with diabetes: may occur due to administration of too much insulin or oral diabetes medications.
Etiology of reactive hypoglycemia in individuals with diabetes:may occur due to a sharp increase in insulin release after a meal, but it usually disappears when the individual eats something.
Etiology of fasting hypoglycemia: usually results from excess insulin or insulin-like substance from external factors such as alcohol or drug ingestion.
Symptoms of hypoglycemia: symptoms often develop in the early morning or after missing a meal and may occasionally occur after exercise; symptoms can include blurred vision, headache, feelings of detachment, slurred speech, and weakness; personality and mental changes vary from anxiety to psychotic behavior; sweating and palpitations may not occur.
Treatment of reactive hypoglycemia: anticholinergic agents may be used in order to slow gastric emptying and intestinal motility and inhibit vagal stimulation of insulin release.
Treatment of fasting hypoglycemia: surgery and drug therapy are generally necessary; medications may include nondiuretic thiazides such as diazoxide to inhibit insulin secretions, streptozocin, and hormones such as glucagon or glucocorticoids.
Discuss the relationship of diabetes to each of the following disorders:
Atherosclerosis: Hyperglycemia (a complication of diabetes) directly affects the structure of the basement membrane of the vessels. This thickening and decreased flexibility of the vessel increase blood pressure and contribute to the acceleration of atherosclerosis. In larger vessels, the intima may enlarge significantly and accumulate intracellular and extracellular lipids, necrotic debris, and calcium, resulting in the development of advanced, complex atherosclerotic lesions.
Nephropathy: The kidneys are responsible for filtering the glucose in the blood, so when blood glucose levels are high they are put under a lot of strain. Over time, the kidneys ability to filter out waste products from the blood becomes impaired. As a result, protein winds up in the urine, which is indicative of the beginning of kidney disease.
Neuropathy: While 60-70% of individuals with diabetes develop some form of neuropathy, it most often develops in those individuals who have had diabetes for at least 25 years, have trouble controlling their blood glucose levels, or have uncontrolled diabetes. It is a result of nerve damage caused by prolonged elevated levels of blood glucose and fat.
Retinopathy: It occurs when the blood vessels of the retina are damaged by prolonged elevated levels of blood glucose.
Cystic Fibrosis: Cystic fibrosis-related diabetes (CFRD) can only occur in diabetic individuals that already have cystic fibrosis. The pancreas is damaged by the buildup of mucus, which prevents it from producing normal amounts of insulin.
Management
Describe “pattern management” in diabetes care.
Pattern management is a process in which patients are taught to identify patterns in their blood glucose level readings and what to do to bring their blood glucose back to their target range. When teaching patients pattern management, you are helping them become more aware about how their daily actions impact their BG levels and providing them with education on how to manage their diabetes. The development of the patient’s pattern is based on their BG levels over an extended period of time as well as the actions that contributed to those levels. Therefore, patients need to keep track of a lot of BG values and what they did throughout each day, and then use the data to assess what factors contributed to changes in their BG levels. The patient has successfully developed a pattern when they are able to take their readings at the same time every day and the readings are consistently in a certain range. Pattern management gives the patient more confidence in their ability to control their diabetes, and better control leads to a reduced risk of developing complications.
List and discuss factors which affect insulin requirements.
Blood glucose levels: Patient’s blood glucose levels need to be within a certain range, so fluctuations in BG levels can change the amount of insulin needed. If levels are elevated, more insulin may be needed, and if levels are low, less insulin may be needed.
Meal composition/hydration status: The timing and dosage of insulin are also affected by meals and hydration status. More insulin may be needed for a meal that is higher in carbohydrates. If the patient is dehydrated, it will take longer for the insulin to move throughout the body, so they may need to take it earlier.
Physical activity: During exercise glucagon is needed, not insulin, because the body uses more glucose which causes blood levels to drop. Therefore, insulin requirements during exercise are reduced. To properly calculate doses, the patient needs to be aware of changes in glucose levels during and after exercise.
Sickness: Illness leads to increased blood glucose levels, so more insulin is needed to bring levels back to normal.
Body mass: Larger individuals need more insulin.
Insulin resistance: Those with T2D are insulin resistant, so they need more insulin.
When is the use of oral hypoglycemic agents indicated? What adverse side effects are associated with their use?
Oral hypoglycemic agents (OHA) are indicated for use in individuals with type 2 diabetes. Therapy with a single class of OHA may be indicated in those patients who are recently or newly diagnosed, especially if they are symptomatic. An OHA is also used for those patients who cannot achieve adequate BG control through diet and exercise alone. Side effects of OHA include feelings of dizziness, drowsiness, sickness, fullness or constipation, as well as heartburn, stomach pain, stomach discomfort, or frequent urination.
What special considerations must be given to children with diabetes?
Being diagnosed with diabetes can be difficult to deal with at any age, but it can be particularly difficult for children because they are still developing emotionally, and they often think of themselves in relation to their peers, so diabetes can make them feel different. It may help some children to explain to their classmates and friends what diabetes is and show them how their supplies work. However, if a child does not want to tell their friends and classmates about their diagnosis right away, it is important to respect their decision and not push them. Regardless of whether or not they want to tell their peers, it is necessary to inform the school nurse, principal, and their teachers that the child has diabetes and communicate the child’s diabetes management needs and the diabetes-related tasks that need to be performed. This applies to any other facility or activity the child is being sent to, such as camp or a friend’s house for a sleep over – an adult must be informed of the child’s condition and management needs. Ensuring that someone is aware of the child’s condition and how to help and assist them if necessary allows the child to have fun safely and be just like any other kid!
What effect does dietary fiber have on blood glucose levels?
Even though fiber is a type of carbohydrate, it doesn’t contribute any calories because the body doesn’t break it down, and it doesn’t raise blood glucose levels. Therefore, if someone is using carbohydrate counting for meal planning, they can subtract the grams of fiber from the total grams of CHO being eaten. Fiber is a great addition to the diet for individuals with diabetes.
Discuss the use of sugar substitutes in the diabetic diet. Include in your discussion, safety levels as established by the FDA.
Sugar substitutes provide the same, if not more, sweetness as actual sugar but they have a much smaller effect on blood sugar levels.For individuals following a diabetic diet, replacing foods containing real sugar with those containing sugar substitutes can be a good way to help control BG levels. Additionally, because most of them are so much sweeter than regular table sugar, only small amounts are needed. The seven nonnutritive sweeteners approved by the FDA are aspartame, acesulfame potassium, luo han guo (monk) fruit extract, neotame, saccharin, stevia and sucralose. The FDA has determined that all seven of these are safe for general use in the U.S. (including pregnant and lactating women), and they each have a set ADI level. There is an exception for aspartame use in people with phenylketonuria (PKU). Individuals with PKU lack the enzyme that breaks down phenylalanine and if they consume foods containing this amino acid it can accumulate in the body and cause damage to the brain and central nervous system. Since aspartame changes to phenylalanine and aspartic acid when it enters the digestive system, individuals with PKU need to avoid foods and drinks that contain it.
What is the general recommended distribution of macronutrients for patients on diabetic diets? What is the recommended distribution of macronutrients for patients with gestational diabetes?
Recommended distribution of macronutrients for patients on diabetic diets:
- CHO = 45-55 % of total kcals
- Fats= 30% of total kcals, < 10% of total kcals as saturated fat, < 300 mg cholesterol/day
- Protein= 15-20% of total kcals
- Fiber= 25-30 gm/d
Recommended distribution of macronutrients for patients with gestational diabetes:
- CHO = a minimum of 175 g/d to provide glucose for the fetal brain and to prevent ketosis; < 45% of total kcals to prevent hyperglycemia
- Fats= 20-35% of total kcals, < 10% of total kcals as saturated fat, < 300 mg cholesterol/day
- Protein= 10-35% of total kcals
Briefly describe the following programs which may be used in planning diabetic meal patterns:
Exchange list system: A method for planning food intake that provides uniformity in meal planning and allows a wide variety of foods to be included in the diet. Uses the concept of “exchange” or substitution of different foods within each of three groups: carbohydrate (starch, fruit, milk non-starchy vegetables, and other carbohydrates), meat and meat substitutes (very lean meats, lean meats, medium-fat meats, high-fat meats), and fats (mono- and poly- unsaturated, saturated). The exchange lists group foods together because they are alike – foods on each list have about the same amount of carbohydrate, protein, fat and calories. In the amounts given, all choices on each list are equal and any food on the list can be exchanged or traded for any other food on the list.
Glycemic Index/ Glycemic Load: An eating plan based on how foods affect your blood sugar level. Carbohydrates-containing foods are ranked on a scale from 0 to 100 according to the extent to which they raise blood glucose levels after eating. Foods that are rapidly digested, absorbed and metabolized and result in marked fluctuations in BG levels have a high glycemic index. Low glycemic index foods are those that produce smaller fluctuations in blood glucose and insulin levels.
Carbohydrate Counting: This is a meal- planning approach that concentrates on the total amount of carbohydrate eaten at meals and in snacks and is based on research demonstrating that consistent intake of a wide variety of CHOs results in similar post-prandial glucose responses. The total amount of daily carbohydrate intake, not its source, is the focus of this meal planning approach. It involves counting the amount of carbohydrates being consumed on a daily basis, with 45-55% of total calories coming from carbohydrates. With this method, carbohydrates can be counted in one of two ways: (1) 15 g of carbohydrates counts as one carbohydrate choice, or (2) use the information provided on the food label or other sources of nutrient analysis to count the total grams of CHOs in a meal or snack.
How might having an eating disorder impact a person with diabetes?
Bulimia is the most common eating disorder in women with type 1 diabetes and binge eating disorder is most common in women with type 2 diabetes. Because both diabetes and eating disorders involve attention to body states, weight management, and control of food, some people develop a pattern in which they use the disease to justify or camouflage the disorder. The complications of both diabetes and eating disorders can be serious or even fatal, so a combination of the two has the very real potential for catastrophic complications, including death. In people with diabetes, eating disorders can lead to poor metabolic control and repeated hospitalizations for dangerously high or low blood sugar. Chronic poor blood sugar control leads to long-term complications, such as eye, kidney, and nerve damage.
Jane is a 24-year-old college senior who was diagnosed as having Type 1 Diabetes at the age of 12. Jane is 5’5″ tall and weighs 118 lbs. She takes an injection of 25 units Lantus each evening and 8 units Lispro with each meal.
(a) What would be the appropriate diet prescription for Jane?
Calorie needs based on current body weight (54kg) = 1610 – 1890 calories (30-35kcal/kg)
Based on her estimated needs, the appropriate diet prescription for Jane is an 1800 calorie diabetic diet
(b) Using the principles of CHO counting, translate this diet prescription into a meal pattern.
Calorie distribution (based on 50% CHO, 20% Protein, 30% Fat):
- CHO= 900 calories/ / 4g/kcal = 225 g / 15 g per CHO exchange = 15 exchanges/d
- Protein= 360 calories / 4g/kcal = 90 g/d
- Fat= 540 calories / 9g/kcal = 60 g/d
|
Food Group |
Total # of Exchanges | Breakfast | Lunch | Dinner | Snacks |
|
Starches |
9 | 2 | 3 | 3 |
1 |
|
Fruit |
3 | 1 | —- | 1 |
1 |
|
Milk |
2 | 1 | —- | —- |
1 |
|
Meats |
6 | 1 | 2 | 3 | —- |
| Fats | 4 | 1 | 1 | 2 |
—- |
| Veggies | 3 | —- | 2 | 1 |
—- |
(c) Using the principles of CHO counting, plan a menu for one day for Jane.
|
Food Group |
Breakfast | Lunch | Dinner | Snacks |
| Starches | 1 cup oatmeal (2) | 2 slices wheat bread (2) + ¼ large baked potato with skin (1) | 1 cup brown rice (3) |
3 cups popcorn, low fat/no butter (1) |
|
Fruit |
1 small banana (1) | —- | 1 small apple (1) | ¾ cup blueberries (1) |
| Milk | 1 cup skim milk (1) | —- | —- |
1 cup non-fat, fruit-flavored yogurt (1) |
|
Meats |
1 hard-boiled egg (1) | 2 oz sliced turkey (2) | 3 oz baked chicken (3) | —- |
|
Fats |
1 TBSP peanut butter (1) | 1 TBSP salad dressing (1) | 2 tsp margarine (2) |
—- |
| Non-Starchy Veggies | —- | 2 cups tomato and cucumber salad (2) | 1 cup cooked broccoli (1) |
—- |
Mr. Doe, age 39, is a bank executive who has just been diagnosed as having Type 2 Diabetes. Mr. Doe is 5’11” tall and weighs 205 lbs. His blood glucose level is 190 mg/dl. Neither insulin nor an oral hypoglycemic agent is ordered.
(a) What would be the appropriate diet prescription for Mr. Doe?
Because he is overweight, calorie needs are based on his IBW (78kg) = 1950 – 2340 calories (25-30kcal/kg)
Based on his estimated needs, the appropriate diet prescription is a 2000 calorie diabetic diet
(b) Using the principles of CHO counting, translate this diet prescription into a meal pattern.
Calorie distribution(based on 50% CHO, 20% Protein, 30% Fat):
- CHO= 1000 calories/ / 4g/kcal = 250 g / 15 g per CHO exchange = 17 exchanges/d
- Protein= 400 calories / 4g/kcal = 100 g/d
- Fat= 600 calories / 9g/kcal = 67 g/d
|
Food Group |
Total # of Exchanges | Breakfast | Lunch | Dinner | Snacks |
|
Starches |
9 | 2 | 3 | 3 |
1 |
| Fruit | 4 | 1 | —- | 1 |
2 |
|
Milk |
3 | 1 | 1 | —- | 1 |
| Meats | 6 | 1 | 2 | 3 |
—- |
|
Fats |
5 | 2 | 1 | 2 | —- |
| Non- Starchy Veggies | 4 | —- | 2 | 2 |
—- |
(c) Using the principles of CHO counting, plan a menu for one day for Mr. Doe.
|
Food Group |
Breakfast | Lunch | Dinner | Snacks |
| Starches | 1 cup oatmeal (2) | 2 slices wheat bread (2) + ¼ large baked potato with skin (1) | 1 cup brown rice (3) |
3 cups popcorn, low fat/no butter (1) |
|
Fruit |
1 small banana (1) | —- | 1 small apple (1) | ¼ cup dried fruit (2) |
|
Milk |
1 cup skim milk (1) | 1 envelope hot cocoa mix, sugar-free (1) | —- |
1 cup non-fat, fruit-flavored yogurt (1) |
| Meats | 1 hard-boiled egg (1) | 2 oz sliced turkey (2) | 3 oz baked chicken (3) |
—- |
|
Fats |
2 TBSP peanut butter (2) | 1 TBSP salad dressing (1) | 2 tsp margarine (2) | —- |
| Non-Starchy Veggies | —- | 2 cups tomato and cucumber salad (2) | 1 cup cooked broccoli (2) |
—- |
