Objective: To compare serum lipid level responses of women and men with hypercholesterolemia to an American Heart Association (AHA) step 1 diet.
Design: Sixty-three women and 99 men with varying degrees of hypercholesterolemia were instructed on an AHA step 1 diet. Subjects were followed up on a biweekly basis with individual visits and group classes for 8 weeks.
Setting: Outpatient clinic facility of the Metabolic Research Group, University of Kentucky, Lexington.
Subjects/samples: Through community cholesterol screenings, we recruited 76 women and 108 men aged 30 to 70 years who were within 80% to 130% of their ideal body weight. Serum cholesterol levels were between 5.17 mmol/L and 8.99 mmol/L and serum triglyceride levels when subjects were fasting were less than 5.08 mmol/L. Sixty-three women and 99 men completed the study.
Intervention: Subjects followed an AHA step 1 diet (30% of energy from fat, 50 to 60% of energy from carbohydrate, 10 to 20% of energy from protein, and less than 300 mg cholesterol per day) for 8 weeks.
Main outcome measures: Serum lipid levels, nutrient intake, and body weight.
Statistical analyses performed: Subjects were divided into three groups according to initial serum cholesterol levels (mild = 5.17 to 6.17 mmol/L; moderate = 6.20 to 6.95 mmol/L; severe = > or = 6.98 mmol/L). Within-individual changes in nutrient intakes, body weights, and serum lipid levels were analyzed using dependent t tests. Between-group comparisons were made using analysis of variance (ANOVA). When significant differences were found using ANOVA, differences between groups were evaluated with the Tukey test.
Results: All subjects tolerated the diet well and average dietary adherence was good, as assessed by a food frequency questionnaire and analysis of 3-day diet records. Serum total cholesterol levels decreased 9.2% overall for women (P < .001) and 7.2% for men (P < .001); serum low-density lipoprotein cholesterol levels decreased 9.2% for women and 9.8% for men; and serum high-density lipoprotein cholesterol levels decreased 3.6% for women and 2.8% for men. Mean serum triglyceride levels decreased significantly for women but not for men. No significant differences were found in the responses of women and men in the corresponding groups. Women and men with higher initial serum cholesterol values showed significantly greater hypocholesterolemic responses to diet than those with lower initial serum cholesterol values.
Applications/conclusions: The findings of this study confirm the beneficial role of dietary intervention for reducing atherogenic serum lipid levels in women and men.