Menopausal status, age at natural menopause and risk of diabetes in China: a 10-year prospective study of 300,000 women.

BACKGROUND: Menopause characteristics have been implicated in future health consequences, yet little is known about its relevance to diabetes. We examined the associations of menopausal status and age at natural menopause with diabetes risk in Chinese women. METHODS: We used prospective data of the China Kadoorie Biobank study that recruited 302,522 women aged 30-79 years in 2004-2008 from 10 areas across China. During average 10.8 years of follow-up, 11,459 incident diabetes cases were recorded among 281,319 women without prior diabetes diagnosis at baseline. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for incident diabetes associated with menopausal status and age at natural menopause. RESULTS: Overall, the mean (SD) age at natural menopause was 48.2 (4.4) years among 141,789 post-menopausal women. Naturally peri-, or post-menopausal women were at higher risk of diabetes, with HRs of 1.17 (95% CI 1.06-1.29) and 1.15 (1.06-1.25) compared with pre-menopausal women, adjusting for several potential confounders. Among women who had natural menopause, the HR of diabetes was 1.14 (1.01-1.30), 1.01 (0.93-1.09), 1.10 (1.04-1.16), and 1.10 (1.01-1.20) for menopause at ages less than 40, 40-44, 50-53, and 54 years or older, respectively, relative to 45-49 years. CONCLUSIONS: In this study, we found that women with naturally peri-, or post-menopausal status had higher risk of developing diabetes. Besides, among the post-menopausal women, both earlier and later age at natural menopause were associated with increased risk of diabetes.