About 1 in 5 girls with pediatric type 2 diabetes (T2D) also has polycystic ovary syndrome (PCOS), according to a systematic review and meta-analysis in JAMA Network Open.
“T2D in youth is on the rise. It is an aggressive disease with high treatment failure rates,” said senior author M. Constantine Samaan, MD, MSc, an associate professor of pediatrics at McMaster University in Hamilton, Ontario, Canada. “While we know that PCOS occurs in girls with T2D, the scale of this condition is not fully known. Our group focused on understanding the global prevalence of PCOS in girls with T2D.”
For the review, the authors devised a search strategy that examined information across several literature databases.
The analysis comprised 470 girls from 6 studies, and the prevalence of PCOS in girls with T2D was 19.58%.
Because heterogeneity among studies was moderate to high, the authors conducted another analysis in which only the studies that reported the exact diagnostic criteria of PCOS were included. This second analysis showed that the prevalence was 24.04%.
“The biggest surprise was that we discovered that girls with T2D were at least twice as likely to have PCOS than those without diabetes,” Samaan told Contemporary OB/GYN®.
In the literature, up to 1 in 9 girls with T2D are diagnosed with PCOS, “but there is a wide range in those figures,” Samaan said. “Our calculation of nearly one in five may in reality be even higher.”
The link between PCOS and T2D in adults is bidirectional, with insulin resistance playing a pivotal role in the pathogenesis of PCOS. “Studies have shown that girls with PCOS have decreased insulin sensitivity and compensatory hyperinsulinemia, which is associated with T2D risk,” Samaan said.
Another potential mechanism that may lead to both insulin resistance and hyperandrogenism is lipotoxicity.
“One of the important findings of the study was that there were no data to determine the association of obesity and race with PCOS risk, which are important associations of T2D,” said Samaan, a staff physician in pediatric endocrinology at McMaster Children's Hospital in Hamilton. “Obesity is considered the main driver of T2D, but some girls with PCOS are neither overweight nor obese. Also, non-Caucasians have a higher risk for T2D than Caucasians.”
But Samaan said the results of the meta-analysis should be cautiously considered because it included studies of larger numbers of girls that did not report the criteria used to diagnose PCOS, “which is a challenge during adolescence.”
Considering that T2D has other associated morbidities, such as fatty liver disease, sleep apnea, abnormal lipids, and hypertension, “the burden of care on these girls is significant,” he said. “Health care providers must be aware of the scale of PCOS in T2D patients, and ask patients about their periods, but also make patients aware of the risk of PCOS with T2D.”
Samaan also noted that it is critical that active screening for PCOS in girls with T2D be initiated at diabetes diagnosis and follows international evidence-based guidelines for diagnosing PCOS in adolescents, as there are treatments that can be offered to manage PCOS.
“In addition, further studies need to estimate some of the drivers of PCOS in these girls, and more molecular studies are required to determine the exact mechanisms of PCOS in T2D,” he said.