Women who approach menopause before the age of 45 have a higher risk of heart disease and stroke, but early menopause does not increase the risk of acquiring diabetes, according to a large new study that calls into question long-held ideas in women's health studies. 

Menopause, The Menopause Society's peer-reviewed journal, published the findings from a large-scale examination of approximately 147,000 women online. Researchers followed participants for an average of 14.5 years to see if the age or type of menopause affected the incidence of diabetes. 

Menopause is the stage of life in which a woman's monthly periods stop permanently, signalling the end of her reproductive years. It can occur spontaneously with ageing or can be caused surgically, such as after the ovaries are removed. Because menopause is frequently followed by weight gain, changes in fat distribution, and decreased sensitivity to insulin—the hormone that regulates blood sugar—scientists have long thought that women who go through menopause early may have a higher risk of diabetes. 

To test this hypothesis, researchers examined data from the UK Biobank, a massive health database. The average age of the women in the research was 60 years, with almost 60% classed as overweight or obese. During the follow-up period, approximately 6,600 women, or 4.5%, were diagnosed with diabetes. 

At first look, diabetes appeared to be slightly more common among women who had menopause earlier, with 5.2% impacted against 4.2% among those who experienced menopause later. However, when researchers controlled for other influencing factors such as body weight, smoking habits, food, and medication use, the apparent association vanished. 

Simply put, early menopause was not the underlying cause. Other factors included "confounders"—background influences that can make two things appear related when they are not. For example, if more women in early menopause smoke or are obese, those characteristics, rather than menopause timing, may account for the higher diabetes incidence. 

The study discovered that diabetes risk was significantly higher among women who smoked (7.5%), were obese (10.8%), did not consume vegetables (6.8%), took cholesterol-lowering medicine (10%), or consumed a lot of added salt (7%). These lifestyle and cardiovascular risk factors, rather than reproductive history, were the primary causes of diabetes. 

"The results of this study highlight that, although postmenopausal women are at increased risk for diabetes, it does not appear to be related to the age at menopause onset or whether menopause occurs naturally or due to surgery but rather to cardiovascular and lifestyle risk factors," says Dr Stephanie Faubion, medical director of The Menopause Women's Health Society. She stated that this is encouraging because blood pressure, cholesterol levels, smoking, nutrition, and physical activity can all be changed, but the age at which menopause occurs cannot. 

Researchers stated that further research is needed to better understand how early or premature menopause is associated with long-term sickness and death, particularly through heart-related pathways. Such evidence could help improve preventative and screening measures for women who are at a higher overall risk. 

The study, titled "Timing and type of menopause are not risk factors for the onset of diabetes: a UK Biobank cohort study", emphasises an important public health message: maintaining heart health and adopting better lifestyles remain critical to lowering diabetes risk throughout midlife and beyond.