A 58-year-old man had a myocardial infarction 1 year ago, which was the first major illness in his life. He now wants to prevent another acute coronary event and is advised to begin a program of exercise and to change his diet. A reduction in the level of which of the following serum laboratory findings 1 year later would best indicate the success of his diet and exercise regimen?

Reduced cholesterol, particularly LDL cholesterol, with the same or increased HDL cholesterol level, indicates a reduced risk of atherosclerotic complications. Atherosclerosis is multifactorial, but a modification of diet (i.e., reduction in total dietary fat and cholesterol) with increased exercise is the best method of reducing risk for most individuals. Atheromatous plaques that have formed can be reduced, albeit over months to years, but plaque regression yield an outcome better than drug or surgical therapy. Glucose is a measure of control of diabetes mellitus. Potassium, calcium, and renin values can be altered with some forms of hypertension, one of several risk factors for atherosclerosis.