Early menopause ups the risk of developing type 2 diabetes

Women who have an early natural menopause have 2.5 times the risk of developing type 2 diabetes as compared to women who have normal menopause reports the results of a large population based study published online July 18, 2017 in Journal Diabetologia.

Taulant Muka, MD, PhD, of Erasmus University Medical Center, Rotterdam, Netherlands, and colleagues write, "In this large population-based study of postmenopausal women free of type 2 diabetes at baseline, we showed that early onset of natural menopause is associated with an increased risk of type 2 diabetes, independent of potential intermediate risk factors for type 2 diabetes (including body mass index [BMI], glucose, and insulin levels) and levels of endogenous sex hormones and SHBG [sex hormone-binding globulin]."

Menopause is a major transition point in women’s life and declining estrogen levels predispose her to increase risk of cardiovascular disease. But, few studies have examined the association between age at menopause and risk of developing type 2 diabetes. Few cross-sectional studies have yielded conflicting results because beside declining hormonal levels, menopausal weight gain, increase in visceral fat and impaired glucose metabolism may also play a part.

This study examined data from Rotterdam study and recruited 3639 women in the final analysis. The Rotterdam Elderly Study is a prospective cohort study in the Ommoord district in the city of Rotterdam, the Netherlands aimed to investigate the risk factors of cardiovascular, neurological, ophthalmological and endocrine diseases in the elderly.

All the women in the current study have attained natural menopause and did not have diabetes at the time of enrollment. The mean age at of woman  was 66.9 (9.6) years, the mean age at natural menopause was 50.0 (4.4) years with median time elapsed since menopause was 15.0 years. The women were stratified into 4 groups according to age at menopause: premature (< 40 years), early (40–44 years), normal (45–55 years), or late (> 55 years).

An analysis of the study cohort showed that 348 women (9.6%) developed type2 diabetes during a median follow up of 9.2 years after adjusting for confounders like age, BMI, glucose and insulin levels, smoking, HRT and genetics. Late menopause is a significant protective factor as compared to premature and early menopause.

Women with late menopause were protected against developing diabetes, and the risk increased as the age at natural menopause decreased. The risk was nearly 4 times higher in women with premature menopause (HR, 3.7)  twice   in women with early menopause (HR, 2.4) and 60% more in women with normal menopause (HR, 1.6; P < 0.001) .

For each 1year delay in onset of menopause, the risk of developing diabetes was lowered by 4% (HR, 0.96).

The authors could not account for the mechanism linking age at natural menopause with development of type 2 diabetes. Earlier data have shown that natural early menopause is a sign of not only reproductive aging but also early somatic aging and all its cardiometabolic consequences. Hence, early menopause can be a good predictor of future general health including type 2 diabetes.

But, the results remained the same after adjusting for the shared genetic factors, so the pathophysiology is unclear and requires more studies in future.

The authors concluded,” The Early onset of natural menopause is an independent marker of type 2 diabetes risk in postmenopausal women. Future studies are needed to examine the mechanisms behind this association and explore whether the timing of natural menopause can add value to diabetes prediction and prevention.”

The full text can be accessed here.