Test Your Knowledge

A. Intra-abdominal obesity has a greater supply of capillaries, making it more metabolically active than subcutaneous fat or fat in the hips and thighs. As a result, there is a greater turnover of free fatty acids. In the liver, these free fatty acids contribute to insulin resistance. Answers B, C, and D are incorrect because these are not mechanisms by which central obesity contributes to increased insulin resistance.

A. Weight loss of 10 kg can be expected to reduce systolic blood pressure (SBP) by 5 to 20 mmHg. Restricting salt intake (B) to 2.4 g per day or alcohol intake (D) to less than 2 drinks per day only reduces SBP by 2 to 8 mmHg and 2 to 4 mmHg, respectively. Aerobic exercise (C) 30 minutes daily reduces SBP by 4 to 9 mmHg.

A. Exercise improves insulin sensitivity, increases HDL, and improves strength and physical work capacity. It also reduces plasma triglycerides and cholesterol levels and enhances fibrolysis, making A the only correct choice.

D. The calculation is as follows: Prebreakfast blood glucose (205 mg/dL) minus his target blood glucose (100 mg/dL) equals 105 mg/dL. Multiply the difference (105 mg/dL) by his correction factor (1 unit per 50 mg/dL) to equal 2 units. Multiply his calculated breakfast carbohydrate intake (50 g) by his insulin-to-carbohydrate ratio (1 unit per 12 g of carbohydrate) to equal 4 units. Add the amount of correction insulin (2 units) to the amount of insulin to compensate for the meal (4 units) to equal 6 units of aspart insulin before breakfast.