Hormone replacement therapy and risk for coronary heart disease. Data from the CORA-study--a case-control study on women with incident coronary heart disease.

BACKGROUND

Hormone replacement therapy (HRT) has been suggested to prevent cardiovascular disease, while some intervention studies have shed doubt on this concept. Thus, uncertainty remains whether current HRT use is beneficial as to cardiovascular disease or may even be harmful.

OBJECTIVES

This research investigates the association of hormone replacement therapy, risk factors and lifestyle characteristics with the manifestation of coronary heart disease in current HRT users versus never users.

DESIGN

The coronary risk factors for atherosclerosis in women study (CORA-study) provide clinical and biochemical parameters and data on lifestyle in 200 consecutive pre- and postmenopausal women with incident coronary heart disease compared to 255 age-matched population-based controls, of which 87.9% were postmenopausal.

RESULTS

Significantly more controls than cases used currently HRT for a median of 9.5 years (32.9% versus 20.2%), while 50.0% of cases and 42.5% of controls had never used HRT (p<0.02). Compared to women who never used HRT, current users ate less meat and sausage, had a significantly lower BMI and waist-to-hip ratio and a lower prevalence of hypertension, insulin resistance and diabetes. However, current users among cases were often smokers and smoked significantly more cigarettes than never users. In a multivariate analysis the risk of current HRT users for coronary artery disease was 57% lower than the risk of never users (odds ratio 0.428, CI 0.206-0.860, p<0.02). Adjustment for conventional and dietary risk factors revealed neither current HRT use, nor HRT use combined with smoking as independent risk factors.

CONCLUSIONS

These data from the CORA-study are not compatible with an adverse impact of hormone replacement therapy on cardiovascular disease, rather support the notion of beneficial effects of HRT on weight, central adiposity, insulin sensitivity and blood pressure. Yet, the data do not support the presumption of a general healthy user effect in women on HRT either. Rather, in some women adverse lifestyle habits, especially intense smoking, appear to counteract possible beneficial effects of HRT.