Problem 16
Calculation of Body Mass Index A biochemistry professor weighs \(260 \mathrm{lb}(118 \mathrm{~kg})\) and is 5 feet 8 inches \((173 \mathrm{~cm})\) tall. What is his body mass index (BMI)? How much weight would he have to lose to bring his BMI down to 25 (normal)?
Problem 18
Effects of a Deleted Insulin Receptor A strain of mice specifically lacking the insulin receptor of liver is found to have mild fasting hyperglycemia (blood glucose \(=132 \mathrm{mg} / \mathrm{dL}\), vs. \(101 \mathrm{mg} / \mathrm{dL}\) in controls) and a more striking hyperglycemia in the fed state (glucose \(=363 \mathrm{mg} / \mathrm{dL}\), vs. \(135 \mathrm{mg} / \mathrm{dL}\) in controls). The mice have higher than normal levels of glucose 6-phosphatase in the liver and elevated levels of insulin in the blood. Explain these observations.
Problem 19
Decisions on Drug Safety The drug rosiglitazone (Avandia) is effective in lowering blood glucose levels in patients with type 2 diabetes, but a few years after rosiglitazone came into widespread use, it seemed that using the drug came with an increased risk of heart attack. In response, the U.S. Food and Drug Administration (FDA) severely restricted the conditions under which it could be prescribed. Two years later, after additional studies had been completed, the FDA lifted the restrictions, and today rosiglitazone is available by prescription in the United States, with no special limitations. Many other countries ban it completely. If it were your responsibility to decide whether this drug should remain on the market (labeled with suitable warnings about its side effects) or should be withdrawn from the market altogether, what factors would you weigh in making your decision?
Problem 20
Type 2 Diabetes Medication The drugs acarbose (Precose) and miglitol (Glyset), used in the treatment of type 2 diabetes mellitus, inhibit \(a\)-glucosidases in the brush border of the small intestine. These enzymes degrade oligosaccharides derived from glycogen or starch to monosaccharides. Suggest a possible mechanism for the salutary effect of these drugs for individuals with diabetes. What side effects, if any, would you expect from these drugs? Why? (Hint: Review lactose intolerance, p. \(523 .\) )
