Type 2 diabetes risk four times higher in women with PCOS

Polycystic ovary syndrome is a common condition that may put young women at risk of type 2 diabetes.

Polycystic ovary syndrome is a widespread condition among women of reproductive age, and a new study suggests that it may also put these women at a significant risk of developing type 2 diabetes.

The research was carried out by Denmark-based scientists and the findings were published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

The Centers for Disease Control and Prevention (CDC) report that polycystic ovary syndrome (PCOS) is the leading cause of female infertility, with up to 5 million women in the United States affected by the condition.

Women with PCOS often have insulin resistance, which is a condition wherein the muscles, fat, and liver do not respond properly to the hormone, so the body keeps producing more of it.

Excessive insulin production is a risk factor for type 2 diabetes. But as the authors of the new research report, there are insufficient prospective population-based studies to date that have studied the connection between PCOS and type 2 diabetes.

The new study aims to fill this research gap. Katrine Hass Rubin, of the Institute of Clinical Research at the University of Southern Denmark in Odense, is the first study author, and the corresponding author is Dorte Glintborg, Ph.D., of the Department of Endocrinology at the Odense University Hospital.

Young women with PCOS at risk

Rubin and colleagues examined data from the Danish National Patient Register as well as patient records from the Odense University Hospital. In total, the study looked at 19,639 premenopausal women who had been diagnosed with PCOS.

The researchers tested the participants' glucose, testosterone, triglycerides, and cholesterol levels. To compare women with PCOS with healthy controls, for each woman with a PCOS diagnosis, the researchers randomly selected three other age-matched PCOS-free women from the Danish National Patient Register. This equaled 54,680 women in total.

Rubin and team adjusted for other potential risk factors for type 2 diabetes, such as age, body mass index (BMI), the use of oral contraceptives, and the number of times the women had given birth.

As Dr. Glintborg summarizes, "In this study, we found that the risk of developing diabetes is four times greater and that diabetes is diagnosed four years earlier in women with PCOS compared to controls."

More specifically, women with PCOS received a type 2 diabetes diagnosis at age 31, on average, and those without the syndrome were diagnosed with type 2 diabetes at age 35, on average.

Regarding other type 2 diabetes risk factors, PCOS correlated positively with BMI, insulin, glucose, and triglyceride levels, but correlated inversely with the number of births.

The authors point out that BMI and glucose levels are the most reliable predictors of type 2 diabetes in women with PCOS. Older age, on the other hand, should not be considered a good predictor, given that the women in the current study were diagnosed with diabetes before the age of 40.

Rubin and colleagues also note that further investigations are needed to assess the impact of oral contraceptives and number of births on type 2 diabetes risk in women with PCOS.

"The increased risk of developing T2D [type 2 diabetes] in PCOS is an important finding [...] Diabetes may develop at a young age and screening for diabetes is important, especially in women who are obese and have PCOS."

Dorte Glintborg, Ph.D.

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