Irregular Menstruation Common in Adolescent Type 2 Diabetes

Megan Moriarty Kelsey, MD, MS

Many adolescent girls with type 2 diabetes (T2D) also experience menstrual dysfunction, a symptom of polycystic ovarian syndrome (PCOS)

The incidence of T2D, once thought to be primarily an adult disease, has been increasing in children for the past few decades. But only 1 therapy designed to treat the disease was approved for children and adolescents, metformin. Thus, in the early 2000s, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) funded the Treatment Options for Type 2 Diabetes in Youth (TODAY) study, a clinical trial designed to test treatment options for T2D in children.

That study, in which Megan Moriarty Kelsey, MD, MS, an associate professor of pediatric endocrinology at the University of Colorado School of Medicine, was an investigator, also provided an opportunity for her to study sex hormones in adolescent females. In adulthood, men and women are equally likely to develop T2D, but in childhood and adolescence, far more girls receive the diagnosis than boys. Researchers do not know why this disparity exists. They do know that 10-20% of women suffer from PCOS, which is known to impact both sex hormones and insulin sensitivity and put the women at risk for developing T2D.

“While we know that [PCOS] leads, down the line, to increased risk for diabetes, we don't know what the prevalence of polycystic ovarian syndrome is in girls who are diagnosed with diabetes early,” Kelsey told MD Magazine.

PCOS can only be diagnosed 2 years after menarche and requires the identification of clinical symptoms, so the researchers could not formally diagnose the girls in the study, but they did collect enough serum samples to check for the hallmark signs.

The TODAY study included 699 participants who were followed for 2 to 6 years. In total, 278 of the girls in the study were eligible for this secondary analysis on menstrual regularity and 190 had stored serum samples available for sex hormone analysis.

The study showed that 21% of the girls with T2D also had menstrual dysfunction suggestive of PCOS. Irregular periods can lead to endometrial hyperplasia, which can cause heavy and painful periods. They can also increase the risk for endometrial cancer.

The samples showed that the girls with irregular periods also had higher testosterone than their counterparts with normal menstruation, which is a main indication of PCOS. It is important to note that while metformin is a drug designed for diabetes, it is also a regularly used treatment, along with hormonal birth control, used to treat PCOS. Since the girls in the study were already taking metformin at baseline to treat diabetes, it may have masked some of the symptoms of PCOS.

“This study showed that despite aggressive treatment of diabetes, that menstrual dysfunction was still present, so it's really important to assess girls with [T2D] for menstrual dysfunction and treat it,” Kelsey emphasized.

The study, “Menstrual Dysfunction in Girls from the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) Study,” was published in the Journal of Clinical Endocrinology & Metabolism.