The association between diabetes type, age of onset, and age at natural menopause: a retrospective cohort study using the Canadian Longitudinal Study on Aging.

OBJECTIVES: With growing incidence of type 1 diabetes (T1D), type 2 diabetes (T2D), and gestational diabetes, more women are expected to spend a larger proportion of their reproductive years living with a diabetes diagnosis. It is important to understand the long-term implications of premenopausal diabetes type on women's reproductive health including their age at natural menopause (ANM). METHODS: Baseline data from the Comprehensive Cohort of Canadian Longitudinal Study on Aging were used. Females who reported premenopausal diagnosis of diabetes were considered exposed. Kaplan-Meier cumulative survivorship estimates and multivariable Cox regression models were used to assess the association between diabetes types and ANM. Sociodemographic, lifestyle, and premenopausal clinical factors were adjusted in the final model as covariates. RESULTS: The sample comprised 11,436 participants, weighted to represent 1,474,412Canadian females aged 45 to 85 years. The median ANM was 52 years. After adjusting for ethnicity, education, smoking, and premenopausal clinical factors, early age of diagnosis of both T1D (<30 years) and T2D (30-39 years) were associated with earlier menopause (T1D, <30: hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.05-2.28; T2D, 30-39: HR, 1.82; 95% CI, 1.12-2.94), as compared with nondiabetics. In addition, later age of diagnosis of T2D (≥40 years) was associated with later ANM (T2D: HR, 0.63; 95% CI, 0.50-0.80). No significant association between gestational diabetes and ANM was noted. CONCLUSIONS: Our results point to early menopause among young women living with a diabetes diagnosis. These findings should allow for more focused research geared toward understanding the long-term health implications of diabetes on women's reproductive health and aging.