Diabetes Mellitus (DM), otherwise known as diabetes, is a “group of diseases characterized by high blood glucose levels that result from defects in the body’s ability to produce and/or use insulin” (American Diabetes Association [ADA], 2012).
Types of Diabetes
- Type I – autoimmune destruction of insulin-producing beta cells; present at birth; may also be referred to as insulin-dependent DM
- Type II – characterized as insulin resistance or decreased ability of pancreas to produce insulin; occurs later in life; may also be referred to as non-insulin-dependent DM
- Gestational – present during pregnancy
How is DM diagnosed?
- less than 100 mg/dL = normal
- 100 to 126 mg/dL impaired fasting glucose (IFG) = prediabetes
- greater than 126 mg/dL = diabetes
- two hour oral glucose test > 200 with glucose load of 75g
- diagnosis of DM must be confirmed on a subsequent day with FBS, TFG or 2 hour glucose tolerance test
Glycosylated hemoglobin, also known as A1C, measures glucose control over the past 3 months.
How do we manage DM?
- For Type I DM, insulin doses are balanced with usual food intake and exercise. Patient must be consistent with the timing of insulin administration and amount of food consumed (especially carbohydrates [CHO]).
- For Type 2 DM, initial dietary management aimed at decreasing calories, fats and simple sugars. Weight loss may help improve glycemic control (recommended weight loss of 5-7%).
- Exercise may help decrease insulin resistance, lower blood glucose levels directly, improve circulation and muscle tone
- a caution about exercise and DM: AVOID exercise if hyperglycemia is present WITH ketosis
- exercise lowers blood glucose levels for about 48 hours after activity
- patients should exercise for 1 hour after a meal or have a 10-15g CHO snack
- patients must check their blood glucose before, during and after exercise
- *do NOT exercise if blood glucose is less than 100
- Drug therapy:
- insulin: given subcutaneously or IV (only Regular can be given IV); different types of insulin with different onsets and peaks**; abdomen is highest rate of absorption followed by the arm, thigh then buttocks
- oral agents: sulfonylureas, meglinitides, metformin
**Insulin types, peaks, onsets and durations
Complications of DM
- caused by too much insulin or by too much exercise compared to the amount of food eaten
- BG < 70 mg/dL
- symptoms: “wet and shaky” – cold sweats, weakness, irritability, pallor, increased HR, confusion, fatigue
- treatment: give a fast acting CHO; when symptoms improve, give a long lasting CHO; Glucagon injection also given
- Diabetic Ketoacidosis
- defined as a profound deficiency in insulin leading to an extremely elevated BG level
most likely occurs in type I DM, but can occur in type II DM during stress or illness
- symptoms: polyuria, dry mouth, thirst, restlessness, sunken eyeballs, Kussmaul respirations, CNS changes, fruity breath, ketonuria
- treatment: 1.) low dose regular insulin (0.1 units) in normal saline (NS) IV; 2.) when BG reaches 250, glucose is added to the IV to prevent hypoglycemia; 3.) replace electrolytes; 4.) prevent cerebral edema and monitor VS, I&O and cardiac status
- Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS)
- a life-threatening syndrome that occurs mainly in type II DM and leads to an extremely elevated BG level
- symptoms: polyuria, dehydration; but NO ketones
- treatment: 1.) rapid replacement of fluid via IV NS or 1/2NS; 2.) administer regular insulin via IV; 3.) when BG reaches 250, glucose is added to the IV to prevent hypoglycemia; 4.) replace electrolytes and monitor VS, I&O and cardiac status
Complications associated with insulin therapy
- Allergy - now rare due to use of human insulin
- Lipodystrophy – occurs if the same injections sites are used subsequently; hypertrophy may also occur is a site is not used for 6 months; this is also rare with human insulin
- Somogyi effect – body abnormally overreacts to hypoglycemia occurring at night or during sleep by increasing BG levels; elevated BG noted on morning BG checks and is associated with undetected hypoglycemia during sleep; treatment with less insulin
- Dawn phenomenon – hyperglycemia is present in the morning due to counter-regulatory hormones released in the predawn hours; treatment by adjusting timing of insulin or increasing insulin