NCEP Diet and Aerobic Exercise Impact on Cholesterol Levels

BACKGROUND: The NCEP is a major public education program providing advice to physicians and the public on management and prevention of coronary heart disease. However, data supporting the advice are derived primarily from middle-aged men, with less data available for women and older individuals. Furthermore, there have been recent reports that when low saturated fat diets such as the NCEP Step One and NCEP Step Two diets, are followed, HDL-cholesterol is lowered as well as LDL-cholesterol. DESIGN NARRATIVE: Randomized, controlled, factorial design powered for men and women separately. One hundred eighty postmenopausal women, 45 through 64 years of age, and 197 men, 30 through 64 years of age, who had low high-density lipoprotein (HDL) cholesterol levels (< or =59 mg per deciliter in women and < or =44 mg per deciliter in men) and moderately elevated levels of low-density lipoprotein (LDL) cholesterol (>125 mg per deciliter but <210 mg per deciliter in women and >125 mg per deciliter but <190 mg per deciliter in men) were enrolled. The subjects were randomly assigned to aerobic exercise, the NCEP Step 2 diet, or diet plus exercise, or to a control group, which received no intervention. The four interventions were delivered for one year: usual care (written dietary materials only with delayed intervention optional), exercise only (supervised, progressive aerobic exercise program at least three times per week), diet only (group and individual dietary instruction on the NCEP Step One/Step Two diet delivered by registered dietitians), and diet plus exercise. At baseline and at the end of one year, measurements were made of blood lipids and lipoproteins, plasma glucose and insulin, glucose tolerance, blood pressure, body composition through hydrostatic weighing and waist and hip circumterences, aerobic fitness (VO2 max), and five unannounced 24-hr. recalls. The primary outcomes measured was HDL-cholesterol, major secondary endpoints included LDL-C, LDL-C/HDL-C ratio, and triglycerides.