Age at natural menopause and stroke mortality: cohort study with 3561 stroke deaths during 37-year follow-up.

BACKGROUND AND PURPOSE Young age at natural menopause has been related to increased cardiovascular mortality, but few studies have examined the relationship with stroke risk specifically. METHODS In a cohort of 19,731 Norwegian women, we analyzed the relationship between age at natural menopause and stroke mortality. A total of 3561 women died of stroke during the 37-year follow-up from 1961 through 1997. Smoking prevalence was low in the underlying population, and use of hormone replacement therapy was very rare. RESULTS No significant linear relationship was found between age at menopause and stroke mortality. A 3-year increase in age at menopause was associated with a 1.0% estimated increase in stroke mortality (95% CI, -1.5, 3.6). No relationships were found for ischemic strokes (271 deaths) or hemorrhagic strokes (389 deaths) when considering the stroke deaths with sufficient information on death certificates. The estimate of the association between age at natural menopause and stroke mortality was hardly influenced by mortality in women with very early (aged <40 years) or late (aged >55 years) menopause, or by a number of possible confounding variables. CONCLUSIONS Age at natural menopause is essentially unrelated to stroke mortality.