Cigarette smoking and age of menopause: a large prospective study

Objectives: One of the possible consequences of tobacco consumption is that it contributes to an earlier age of menopause, though the causal relationship is yet to be confirmed. This study aimed to examine the prospective association between smoking and earlier age of menopause in a cohort of middle age Australian women after adjustment for a number of potential confounders.

Study design: 21-Year follow-up of a cohort prospective study, Brisbane, Australia.

Main outcome measures: Age of menopause measured at the 21-year follow-up. Smoking and menopausal status were assessed by self-report. Other covariates were measured prospectively in the previous follow-ups.

Results: This study is based on 3545 women who provided data on their menopausal status at the 21-year follow-up of the study, and prospective as well as concurrent data on smoking. In univariate analysis tobacco smoking during the reproductive life course, socio-economic status and gravidity were significantly associated with earlier age of menopause. In multivariate analyses women who smoked cigarettes were more likely to experience earlier menopause than non-smokers. Compared to current smokers, risk of early menopause was significantly lower in those women who quit smoking in the past.

Conclusions: The data suggest that the impact of smoking is independent of other covariates associated with both smoking and age of menopause. The findings raise the possibility that effective quit smoking interventions may lead to a later age of menopause, and reduce the risk of adverse health consequences of early menopause.