Prestroke factors associated with poststroke mortality and recovery in older women in the Women's Health Initiative

Objectives: To examine prestroke lifestyle factors associated with poststroke mortality and recovery in older women.

Design: Longitudinal prospective cohort study.

Setting: The Women's Health Initiative (WHI, clinical trials and observational study), 40 clinical centers in the United States.

Participants: WHI participants, women aged 50 to 79, who were stroke-free at baseline (1993/98), with incident stroke before 2005.

Measurements: Participants were followed for mortality through 2010. Prestroke characteristics were from the last examination before the stroke event. Annual follow-up for clinical events ascertained hospitalization for stroke that was subsequently physician adjudicated with medical records. Multivariable regression models were used to analyze factors associated with poststroke mortality and poststroke recovery at hospital discharge (poststroke Glasgow score), adjusting for stroke type.

Results: Of 3,173 women with incident stroke, 1,111 (35%) died. Individuals who were overweight or obese before stroke had lower poststroke mortality than those who were normal weight (obese: hazard ratio (HR) = 0.69, 95% confidence interval (CI) = 0.53-0.88; overweight: HR = 0.72, 95% CI = 0.58-0.90); individuals who were underweight before stroke had nonsignificantly greater poststroke mortality (HR = 2.02, 95% CI = 0.98-4.16, P = .06). Other prestroke factors associated with poststroke mortality included diabetes mellitus (HR = 1.28, 95% CI = 1.01-1.64), current smoking (vs nonsmoker, HR = 2.13, 95% CI = 1.53-3.00), physical inactivity (vs >150 min of exercise per week, HR = 1.39, 95% CI = 1.09-1.78), and lowest physical function quartile (vs highest, HR = 1.54, 95% CI = 1.18-2.02). Prestroke diabetes mellitus was associated with lower odds of good recovery after stroke (odds ratio (OR) = 0.60, 95% CI = 0.44-0.82). Current hormone use before stroke was associated with greater odds of moderate than of severe disability after stroke (OR = 1.29, 95% CI = 1.00-1.66).

Conclusion: Potentially modifiable factors before stroke, including smoking, diabetes mellitus, and being underweight, were associated with greater poststroke mortality in older women. Being overweight or obese and physical activity before stroke were associated with lower poststroke mortality in older women.