A late menopause increases a woman’s risk of developing type 2 diabetes, a study suggests.
US researchers looked at 124,000 women, and found a higher risk for those undergoing the menopause after the age of 55 – the average is 51.
They suggested hormone levels could explain the risk linked to a later menopause.
A Diabetes UK spokeswoman said understanding who was at risk could help target healthy lifestyle advice.
It was already known that women who experience the menopause early, before the age of 45, have a higher risk of type 2 diabetes because a lower level of the female hormone oestrogen is linked to increased body fat, a lower metabolism and higher blood-sugar levels.
Researchers from Kaiser Permanente, a US care provider, looked at data from the Women’s Health Initiative – a wide-ranging national study of post-menopausal women which recruited women aged 50-79 in the mid-1990s and followed them for just over a decade.
The women completed extensive health questionnaires, providing details of their medical conditions and reproductive history.
This paper, published in Menopause, the official journal of the North American Menopause Society, found women who had their final period before the age of 46 were 25% more likely to develop type 2 diabetes, compared with women who had their final period between the ages of 46 and 55.
Those who had their final period after 55 had a 12% increased risk.
Lead researcher Dr Erin LeBlanc said: “Women who start menopause before or after that window should be aware that they are at higher risk, and should be especially vigilant about reducing obesity, eating a healthy diet and exercising.
“These lifestyle changes will help to reduce their risk for type 2 diabetes.”
The length of a woman’s reproductive life – the time from her first period to her last – also appeared to have an effect, according to Dr LeBlanc and her team.
Those whose reproductive cycles were less than 30 years were 37% more likely to develop diabetes than those with a 36-40 year cycle.
Over 45 years was linked to a 23% increased diabetes risk.
The researchers adjusted their results for factors including age, race, weight, contraception, number of pregnancies and the use of hormone replacement therapy.
JoAnn Pinkerton, executive director of the North American Menopause Society, said: “This study suggests that lifetime oestrogen exposure may play a role in the development of type 2 diabetes – women may need an ‘optimal’ amount of oestrogen exposure for best metabolic functioning.”
Dr Emily Burns of Diabetes UK, said: “Understanding who is most at risk of type 2 diabetes is important in order to intervene and prevent the condition from developing where possible.”
She said the study’s findings were significant, but that further work was needed to fully understand why menopause age appeared to be linked to type 2 diabetes in certain women.
Dr Burns added: “We know that the risk of type 2 diabetes can be reduced through weight loss, healthy eating and exercise, and we would recommend that anyone concerned about their risk speak to their healthcare professional and focus on leading a healthy lifestyle.”