Hormone replacement therapy and mortality in 52- to 70-year-old women: the Kuopio Osteoporosis Risk Factor and Prevention Study

Abstract

Objectives: To analyze prospectively the association between hormone replacement therapy (HRT) and mortality in women before old age. Design and methods: A group of 11 667 women (91% of the age cohort of the area) aged 52–62 years from the population-based Kuopio Osteoporosis Risk Factor and Prevention Study were followed for 7 years in 1994–2001. Information about HRT use and health events was obtained from two repeated questionnaires in 1989 and 1994. Information about deaths and causes of death from the follow-up period was obtained from the Statistics Finland. Cox’s proportional-hazards models were used to calculate risk of death related to the use of HRT. Results: At the start of follow-up, 2203 women had used HRT >5 years, 3945 women ≤5 years and 5519 women had never used it. During the follow-up, 361 deaths occurred. Compared with non-users of HRT, the adjusted hazard ratio (HR) of death from any cause was 1.05 (95% confidence interval (CI) 0.80–1.36) in women who used HRT ≤5 years and 1.06 (95% CI 0.78–1.46) in women who used HRT >5 years. The adjusted HR for coronary heart disease (CHD) mortality in women who used HRT ≤5 years was 0.79 (95% CI 0.36–1.73), and in women who used HRT >5 years, 2.16 (95% CI 0.93–4.98). For breast cancer mortality the adjusted HR for ≤5 years of HRT use was 0.96 (95% CI 0.32–2.82) and 2.62 (95% CI 0.98–7.00) for >5 years of HRT use. Conclusions: History of HRT use does not affect overall or CHD mortality in women. More than 5 years of HRT use may increase the risk of breast cancer mortality.