Women with early or normal onset menopause are at an increased risk of developing Type 2 diabetes compared to women with late onset menopause, a new study from the Erasmus University Medical Center in the Netherlands says.
Previous research by the same team has also linked early onset menopause (before the age of 45) to a higher risk of cardiovascular disease and overall mortality. However, those whose menopause occurs between the ages of 50 and 54 are at a reduced risk of cardiovascular disease and mortality.
And while the increased risk is believed to be because of the adverse impacts of menopause on cardiovascular disease risk factors, it’s unclear if age at menopause has any influence on these risk factors, researchers say.
According to the study, Type 2 diabetes is a major risk factor for cardiovascular disease, but that too remains uncertain if age at menopause is associated with an elevated risk of Type 2 diabetes. So the team set out to find if a link between age at natural menopause and the risk of Type 2 diabetes existed.
Researchers looked over the data of 6,816 women (which was then narrowed down to 3,969 women) from the Rotterdam Study, a “population-based, prospective cohort study” done by the Ommoord district of Rotterdam in the Netherlands. Participants were 45 and older and had regular medical exams every three to five years.
Those excluded from the study had, for example, not reached menopause, already had Type 2 diabetes or had a non-natural menopause. Participants’ menopausal status was then monitored using a take-home questionnaire.
Prevalent and incident cases of Type 2 diabetes were obtained using medical records, hospital discharge letters and glucose measurement from visits at both the baseline visits and during followups.
All possible cases of Type 2 diabetes were independently judged by two study physicians with help from an endocrinologist.
Researchers also gathered extensive health backgrounds on participants, which included health status, medical history, medication, smoking and alcohol behaviour, socioeconomic status, educational status, age at first period, number of pregnancies of at least six months, history of cardiovascular disease, blood pressure and use of antihypertensive medications. They also gathered information on several biochemical parameters (like cholesterol) and their physical activity habits.
After pouring over all the information, researchers found that of the 3,639 women without diabetes at baseline, 348 had developed Type 2 diabetes over with a median followup of 9.2 years.
Those with the earliest onset of menopause (under the age of 40) were almost four times more likely to develop Type 2 diabetes. Women who began menopause between the ages of 40 and 44 were 2.4 times more likely to develop Type 2 diabetes, while women who began menopause between 45 and 55 years of age were 60 per cent more likely compared to those who had a later onset of menopause.
The researchers also found that the older the woman was when she began menopause, the risk of developing Type 2 diabetes reduced by four per cent per year.
The study is published in the journal Diabetologia, the journal of the European Association for the Study of Diabetes.
Previous studies have also found associations between the onset age of menopause and other health impacts.
Earlier this year, the North American Menopause Society (NAMS) found that experiencing menopause in older age while taking hormone therapy was associated with an elevated risk of hearing loss.
Another study conducted by NAMS in 2016 found a link between early menopause (before the age of 40) and an increased risk of fractures, despite the use of calcium and vitamin D supplements.