Type A behavior pattern, heart disease risk factors, and estrogen replacement therapy in postmenopausal women: The Rancho Bernardo Study

Cardiovascular disease is the leading cause of death among older American women. Estrogen replacement therapy (ERT) appears to reduce the risk of heart disease. For nearly five decades, the Type A behavior pattern (TABP) has been implicated in the cardiac morbidity and mortality of both men and women, but no studies have examined the use of replacement estrogen or whether ifs association with heart disease risk factors is different in Type A versus Type B women. We examined the effects of ERT and TABP on heart disease risk factors in a large population-based sample. Subjects were 1070 postmenopausal women, aged 50-89 years, who had been participants in the Rancho Bernardo Study. At a clinic visit made during 1984-1987, TABP was assessed with the Bortner Rating Scale, and heart disease risk factors (total cholesterol, high-density and low-density lipoprotein (HDL and LDL), triglycerides, fasting and postchallenge insulin and glucose, and blood pressure) were measured. Based on a median split (median = 154.0) of scores on the Bortner Rating Scale, 52% of these women were classified as Type A. Type A women were significantly younger than Rating women (mean = 68.4 versus 71.0 years, respectively). After adjustment for age, significantly more Type A than Type B women were on ERT (35% versus 24.7%, p = 0.001). Analyses stratified by TABP indicated that within the Type A group, current users of ERT had higher levels of HDL cholesterol (p) = 0.001) and lower levels of LDL cholesterol (p < 0.01), fasting plasma glucose (p < 0.001), and fasting insulin (p < 0.01). Among Type B women, current users of ERT had higher levels of HDL cholesterol (p = 0.07) and triglycerides (p < 0.01), lower levels of LDL cholesterol (p < 0.01), and lower systolic blood pressure (p < 0.05) but no significant differences in either fasting. or postchallenge levels of either plasma glucose or serum insulin (each p < 0.01). Results of this study suggest that ERT may be associated with significant differences in the heart disease risk factor profile in Type A versus Type B women, and these differences may favor Type A women.