Women who begin menopause before the age of 45, or experience premature ovarian failure (menopause before age 40), are at greater risk of developing type 2 diabetes than women with normal, natural menopause, according to a large meta-analysis involving almost 200,000 postmenopausal women.
The findings are being presented at this year's European Association for the Study of Diabetes (EASD) Annual Meeting in Berlin, Germany (1-5 October).
Low levels of oestrogen after the menopause have been linked to impaired glucose metabolism, high blood sugar levels and increased appetite and body fat. Whether age at menopause is associated with type 2 diabetes risk is unclear and previous studies have yielded contradictory results.
Dr Panagiotis Anagnostis from the Aristotle University of Thessaloniki, Thessaloniki, Greece and colleagues did a systematic review and meta-analysis of observational studies examining the effects of early menopause and premature ovarian failure on risk of type 2 diabetes up to the end of January 2018.
Using statistical modelling the researchers compensated for the effects of publication bias, as well as confounding factors such as age, body mass index (BMI), smoking status, level of physical activity, race, type of menopause (surgical or natural) and use of HRT.
Analysis of data from 13 studies involving 191,762 postmenopausal women and 21,664 cases of diabetes, found that women who reached menopause before age 40 were 50% more likely to develop type 2 diabetes than those with normal, natural menopause between the ages of 45 and 55 years. Similarly, women whose fertility came to an end before age 45 were 15% more likely to become diabetic than women with normal onset menopause.
Similar associations emerged when women with early menopause and premature ovarian failure were compared with those who reached menopause at age 45 years or older.
"This is the first meta-analysis to show that both early menopause and premature ovarian failure are linked with increased risk of type 2 diabetes", says Dr Anagnostis. "Women who experience early menopause should be especially vigilant about eating healthily and exercising to help reduce their risk of developing diabetes."
He adds: "Our observational study cannot prove that early menopause causes diabetes but only suggests the possibility of such an effect. Further research is needed to investigate the underlying mechanisms linking early menopause to diabetes and to examine whether timing of natural menopause may help diabetes prediction and prevention."