The average age at which a women hits menopause is 51. In the years that follow, her risk for diabetes goes up dramatically. You can’t blame menopause—entirely. Risk increases with age for everyone—men and women—especially over age 45.

But the hormonal changes that happen with menopause play a role. Starting in the perimenopausal years and accelerating through postmenopause, declining levels of estrogen can lead to rising blood sugar levels and higher insulin levels. Low estrogen also increases a woman’s chances of developing abdominal obesity (e.g., becoming more “apple” shaped), which in turn increases diabetes risk. And women who use hormone therapy, which increases their estrogen levels, have a statistically reduced risk of developing diabetes.

Now researchers have found a new twist. It’s not just going through menopause that increases diabetes risk. It’s how old you are when menopause hits. In this case, being relatively older when you have your last period appears to be a distinct advantage.

Background: Technically, menopause begins one year after a woman’s final menstrual period. For most women, this is between the ages of 45 and 55—the average age is 51. Some women reach menopause earlier due to surgery (such as a hysterectomy in which both ovaries are removed). But some women go through natural menopause between 40 and 44 (early menopause), and some even experience it before age 40 (premature menopause). Other women don’t reach menopause until after age 55 (late menopause).

It’s known that early menopause is associated with increased heart disease risk. But how menopause age affects diabetes risk in women hasn’t been well-researched.

Study: Researchers from the Netherlands examined medical histories, lifestyle information and many other health factors related to about 3,600 women. None of the women had diabetes at the start of the study. All of the women provided the age when they entered menopause. Over an average of 9.2 years of follow-up, 348 of the women developed diabetes.

Finding: After adjusting for known risk factors such as obesity, menopause age still made a big difference…

  • Premature menopause. Women who reached natural menopause before age 40 were nearly four times more likely to develop diabetes than women who reached it after age 55 (late menopause).
  • Early menopause. Women who reached menopause between ages of 40 and 44 were more than twice as likely to develop diabetes as those who reached it after 55.
  • Normal menopause. Even women who reached menopause at so-called normal age (45 to 55 years) had 60% increased risk of developing diabetes compared with women who experienced late menopause.

Overall, for each year of delay reaching menopause, diabetes risk was reduced by 4%.

What about surgical menopause? When the researchers added those numbers in, they found the same statistical phenomenon—the earlier the menopause, the greater the diabetes risk.

Bottom line: While this study can’t identify how menopause age affects diabetes risk, the researchers suggest that it may be a signal of early aging. Whatever the reason, the new research suggests that the age at which you hit menopause is a clue to your future risk of diabetes. According to the National Institutes of Health, every American adult age 45 or older should get tested for diabetes. (The same tests are used to diagnose prediabetes, too.) Yet millions of Americans go undiagnosed. If you hit menopause on the early side, you have a new incentive to get tested as soon as possible.