Objective: Younger age at menopause is associated with overall mortality, and cigarette smoking is the only lifestyle factor influencing this association. However, the combined effects of age at menopause and smoking have never been quantified in terms of survival time. Our aim was to evaluate, in a large cohort of Swedish women, differences in age at death according to age at menopause and smoking status.
Methods: Age at menopause and smoking were assessed, using a self-administered questionnaire, in a population-based cohort of 25,474 women aged 48 to 83 years. Laplace regression was used to calculate differences in median age at death (50th percentile difference [PD]) according to smoking and age at menopause.
Results: Across 16 years of follow-up, 5,942 participants died. The difference in median age at death between women with menopause at 40 years and women with menopause at 60 years was 1.3 years (50th PD, 1.3; 95% CI, 0.3-2.2). Compared with current smokers, former smokers and never smokers had older median age at death-2.5 years (50th PD, 2.5; 95% CI, 1.9-3.1) and 3.6 years (50th PD, 3.6; 95% CI, 3.1-4.1), respectively. When analysis was restricted to current smokers, the difference in age at death between women with menopause at 40 years and women with menopause at 60 years increased to 2.6 years (50th PD, 2.6; 95% CI, 0.8-4.5). No association among never smokers was observed.
Conclusions: Younger age at menopause is linearly associated with shorter survival. This association tends to be stronger among current smokers.