Comparison of the Heart and Estrogen/Progestin Replacement Study (HERS) cohort with women with coronary disease from the National Health and Nutrition Examination Survey III (NHANES III)

Background The Heart and Estrogen/Progestin Replacement Study (HERS) is the first large clinical trial designed to test the efficacy of postmenopausal estrogen/progestin therapy for secondary prevention of coronary heart disease (CHD). To examine the representativeness of the HERS cohort to the general population of postmenopausal women with CHD, we compared the baseline cardiovascular risk factor data from HERS with similar data from women presumed to have CHD from the National Health and Nutrition Examination Survey (NHANES) III. Methods Age, race, and cardiovascular disease risk factors were compared in the 2763 postmenopausal women younger than 80 years old, with a uterus, and with documented CHD in HERS versus 145 similarly aged women with clinical or electrocardiographic evidence of CHD from phase I of NHANES III. Results There were fewer current smokers in HERS (13%) than in the NHANES cohort (21.7%, p = 0.05). Similarly, a history of hypertension was less prevalent in HERS (58.6%) than in the NHANES cohort (69.3%, p = 0.03). Women with fasting triglyceride levels >3.39 mmol/l or fasting glucose revels >16.6 mmol/l were excluded from HERS, resulting in fewer diabetics (22.9% vs 29.5%, p = 0.26) and lower serum triglyceride levels (1.88 mmol/L vs 2.25 mmol/L, p = 0.19) in HERS versus the NHANES cohort. Systolic and diastolic blood pressure, body mass index, physical activity, and total IDL and HDL cholesterol were not significantly different between the two groups. Conclusions The HERS cohort had fewer CHD risk factors than women with myocardial infarction or angina in NHANES Ill, although comparison is hindered by differences in selection criteria. The many women with diabetes and hypertriglyceridemia in the NHANES cohort emphasizes the importance of testing strategies for secondary prevention of CHD in this high-risk subgroup.