It’s long been known that the risk for Type 2 diabetes isn’t evenly spread across the population. For example, American Indians and Alaska Natives are more than twice as likely to have the condition as non-Hispanic white Americans, according to the American Diabetes Association.
But when it comes to sexual orientation, studies on diabetes risk have mostly been limited in their reach and design. So a recent study showing a higher risk of diabetes in lesbian and bisexual women may offer important new insights to researchers, doctors, and the public.
Large group, long duration
The study, published in May 2018 in the journal Diabetes Care, looked at women who participated in a long-term general study called the Nurses’ Health Study II. Participants — all of whom were nurses — ranged from 24 to 44 years old when the study began in 1989, and were followed through 2013.
Among the women included in the analysis, 1,267 identified as lesbian or bisexual, while 92,983 identified as heterosexual. Using a statistical model that looked at self-reported diabetes status over the course of the study, the researchers found that lesbian and bisexual women were 27 percent more likely than their straight peers to have Type 2 diabetes. This difference was greater at a younger age, and got smaller as the women in the study grew older.
One important difference between the two groups was body-mass index (BMI) — a measure of weight that takes height into account. When BMI was controlled for in the researchers’ model, the difference in diabetes risk completely disappeared. This means that BMI may fully account for the higher diabetes risk seen in lesbian and bisexual women — but it doesn’t explain why this group had a higher average BMI, or whether other factors were also at work.
Why the difference?
The study’s results mirror those of previous studies involving other minority groups, according to lead author Heather L. Corliss, PhD, MPH, a professor at the San Diego State University School of Public Health.
”Discrimination and other forms of social disadvantage that disproportionately impact marginalized groups, such as poverty, are associated with increased risk for Type 2 diabetes,” says Corliss. Therefore, she adds, “it is plausible that minority stress contributes to the development of Type 2 diabetes among lesbian and bisexual women.”
In previous studies, minority stress has been associated with certain risks and behaviors — such as depression and tobacco smoking — that are known to increase diabetes risk, Corliss notes. And in the Nurses’ Health Study II, lesbian and bisexual women reported higher levels of depression, tobacco smoking, sedentary behavior, and being a victim of violence than their heterosexual peers. But they also reported more physical activity and a higher-quality diet, so it’s unlikely that traditional “lifestyle factors” explain why this group had a higher risk of Type 2 diabetes.
Studies like this one aren’t about what any individual lesbian or bisexual woman can or should do to reduce her diabetes risk, says Corliss. Rather, they’re about identifying health disparities so that the wider society — including health professionals — can take action to address them.
”Expanding efforts by the public health and medical professions to address the detrimental health impacts of social stigma and minority stress may lead to improved health and wellness among lesbian and bisexual women,” Corliss says. She adds that public health efforts should include prevention, detection, and management of obesity and Type 2 diabetes in this group of women.
The study’s results also suggest, Corliss notes, that doctors should take a patient’s sexual orientation into account, among other factors, when making recommendations for screening related to diabetes and other health conditions.