Chapter 30: Endocrine Pancreas and Pharmacotherapy of Diabetes Mellitus and Hypoglycemia
A 45-year-old woman with type 2 diabetes is noticing an increase in her basal insulin dose needed to achieve the same effect. This is likely because of
a. increased insulin secretion.
b. insulin resistance in target tissues.
c. improper formulation of her insulin.
d. increased glucagon secretion.
e. increased consumption of carbohydrates.
Answer is b. Insulin sensitivity is a quantifiable parameter that is measured as the amount of glucose cleared from the blood in response to a dose of insulin. The failure of normal amounts of insulin to elicit the expected response is referred to as insulin resistance. The major insulin-responsive tissues are skeletal muscle, fat, and liver. Insulin resistance in muscle and fat is generally marked by a decrease in the transport of glucose from the circulation.
A 69-year-old man with type 2 diabetes is hospitalized because of a knee replacement. His blood sugar postsurgery is 215 mg/dL. His hyperglycemia is best managed in the hospital by
a. increasing his metformin dose.
b. increasing his sulfonylurea dose.
d. decreasing his food intake.
e. subcutaneous or intravenous insulin.
Answer is e. Insulin is the cornerstone of treatment of hyperglycemia in hospitalized patients. Intravenous insulin is the treatment of choice, but in patients who are more stable, subcutaneous insulin regimens using a combination of basal and prandial insulin is the standard.
A 56-year-old woman with type 2 diabetes is being treated with metformin and glimepiride. These two drugs act synergistically because glimepiride
a. decreases the clearance of metformin.
b. acts to increase glycogen stores in the liver.
c. stimulates insulin release by binding to a specific site on β cells.
d. increases the activity of AMP-dependent protein kinase (AMPK).
e. decreases glucose reabsorption in the kidney.
Answer is c. Sulfonylureas such as glimepiride stimulate insulin release by binding to a specific site on the β cell KATP channel complex (the sulfonylurea receptor, SUR) and inhibiting its activity (see Figure 30-2).
Figure 30-2. Regulation of insulin secretion from a pancreatic β cell. The ...