Risk factors for mortality in middle-aged women

Many factors contribute to mortality in older women, but their relative importance and independent contribution have been poorly characterized.

From 1990 to 1992, we assessed demographics, lifestyle measures, prevalent disease, medication use, anthropometrics, vital signs, and physical function in 17 748 postmenopausal women. We used proportional hazards modeling to evaluate their association with mortality.

During 9 years of follow-up, 1886 women (10.6%) died. The relative hazard (RH) of death was approximately 1.5 (95% confidence interval [CI], 1.5-1.6) per 5 years of age, 1.4 (95% CI, 1.2-1.6) for a history of heart disease, and 1.9 (95% CI, 1.6-2.3) for a history of breast cancer. Modifiable risk factors associated with mortality included smoking (RH, 3.7 [95% CI, 3.1-4.5] for current smokers with a > or =50 pack-year history) and systolic blood pressure (RH, 1.3 [95% CI, 1.1-1.5], fifth vs first quintile). Elevated waist-hip ratio was associated with higher mortality (RH, 1.3 [95% CI, 1.1-1.5], fifth vs first quintile), but obesity was associated with lower mortality (RH, 0.7 [95% CI, 0.6-0.9] for body mass index [calculated as weight in kilograms divided by the square of height in meters] of >35.0 vs 18.5-25.0). Poor results on the timed Up and Go Test, a measure of physical function, were also strongly associated with mortality (RH, 1.7 [95% CI, 1.4-2.0], fifth vs first quintile).

Simple measures are sufficient to stratify postmenopausal women into groups at high and low risk of dying. Smoking, central obesity, blood pressure, and physical function are potentially modifiable risk factors, although clinical trials are required to demonstrate that change in these factors affects mortality.