Obesity messes with menstrual cycle, promotes PCOS in women with T1D

Among women with type 1 diabetes, obesity is prevalent and puts them at heightened risk of menstrual irregularity and polycystic ovary syndrome (PCOS), a study reports.

Researchers used data from the Australian Longitudinal Study in Women's Health and looked at 15,926 women (mean age, 21 years), of whom 115 had T1D. All participants completed three questionnaires, which were used to evaluate menstrual irregularity, PCOS, and body mass index (BMI), at baseline and yearly intervals. Only 61 women with T1D and 8,332 controls remained at year 2.

Compared with controls, women with T1D had higher baseline weight (median, 70 vs 64 kg) and BMI (median, 25.5 vs 22.9 kg/m²), with more than half of them having a BMI in the overweight or obese category (54.4 percent vs 32.9 percent). At year 2, median BMI increased by 1.11 kg/m² in the T1D group (p=0.04) and by 0.49 kg/m² in the control group (p<0.001), corresponding to median weight increases of 4 and 2 kg over 2 years, respectively.

Menstrual disorders, such as irregular periods, heavy periods, and dysmenorrhea, were highly prevalent in both groups: 47.8 percent of women with T1D and 40.3 percent controls at baseline. On the other hand, significantly more women with T1D had PCOS (16.5 percent vs 5.5 percent; p<0.001), prior pregnancy (21.7 percent vs 13.2 percent; p=0.007), and miscarriage (12.2 percent vs 4.3 percent; p<0.001).

Multivariable log-binomial regression analysis revealed that women with T1D were indeed at increased risk of menstrual irregularity (relative risk [RR], 1.22, 95 percent confidence interval [CI], 1.02–1.46) and PCOS (RR, 2.41, 95 percent CI, 1.70–3.42) compared with controls. Furthermore, obesity conferred a fourfold increased risk of PCOS compared with normal BMI (RR, 3.93, 95 percent CI, 3.51–4.42).

While more longitudinal studies are needed, the present data emphasize the need for increased awareness of reproductive disorders in T1D, particularly in overweight or obese women, according to the researchers.