A study found that midlife women with diabetes, especially those treated with metformin, had a significantly lower risk of developing uterine fibroids. The association varied by menopausal status, with stronger links in premenopausal women.

A recent study published in The Journal of Clinical Endocrinology & Metabolism suggested that diabetes, mainly when treated with metformin, is associated with a lower incidence of uterine fibroids in midlife women. The study also indicated that the relationship between diabetes and fibroid risk may vary depending on menopausal status.

Researchers conducted a prospective cohort study involving participants from the Study of Women’s Health Across the Nation. Over 13 follow-up visits, they examined the association between diabetes, cardiometabolic biomarkers, and the development of uterine fibroids. Fasting blood samples were collected to measure glucose, insulin, and sex hormone–binding globulin (SHBG) levels, along with homeostatic model assessments for insulin resistance (HOMA-IR).

The study analyzed data from 2,570 women with a median age of 45 years, 45% of whom were perimenopausal. Diabetes was present in 3% of participants at baseline and was associated with a 28% lower incidence of fibroid diagnoses. Women receiving diabetes treatment, especially metformin, had an even greater reduction in fibroid risk—51 % lower compared to those without diabetes.

However, cardiometabolic biomarkers like HOMA-IR and insulin levels were not significantly linked to fibroid development overall. The association between these biomarkers and fibroid risk was stronger during premenopause but not during perimenopause.