HT Timing and Cardiovascular Risk: Pendulum Continues Its Swing Toward Reassurance

Analyses from the Women's Health Initiative, the Nurses' Health Study, and other trials have suggested that timing of initiation of hormone therapy fundamentally affects its cardiovascular safety (JW Womens Health Apr 8 2010). Using data from the California Teachers Study (CTS), a prospective cohort study of current and retired female teachers, researchers sought to determine the effects of age at current HT use on coronary heart disease (CHD) incidence and mortality during follow-up. More than 71,000 participants who completed baseline questionnaires in 1995 or 1996 were followed through 2004 or until death. Current HT users (at baseline) were leaner, less likely to smoke, and more likely to exercise and consume alcohol than were former or never users; models were adjusted for these and other potential confounders.

During follow-up (range, 5–7 years), 18.3% of never users, 17.9% of former users, and 6.9% of current users died. Compared with never use, current HT use was associated with substantially lower risk for CHD-related death (hazard ratio, 0.84). This risk reduction was most pronounced in the youngest current HT users (age range, 36–59; HR, 0.38) and gradually diminished with advancing age (age range, 70–84; HR, 0.90). For overall mortality, HR was 0.54 in the youngest current users and approached 1.0 in the oldest current users. Results were similar regardless of HT type (i.e., estrogen-only or estrogen-progestin).