The BMI of patients with polycystic ovary syndrome appeared to be the most important factor in basal metabolic rate, independent of the polycystic ovary syndrome phenotype and insulin resistance, according to Margareta D. Pisarska, MD, who presented the data at the conjoint meeting of the International Federation of Fertility Societies and the American Society for Reproductive Medicine.

“Based on our study — since we do think obesity does play a significant role — we believe it is important for endocrinologists to help counsel these women in a fashion similar to those who are obese by emphasizing that weight loss and lowering BMI are important,” Pisarska, director of the division of reproductive endocrinology and infertility; director of the Fertility and Reproductive Medicine Center at Cedars-Sinai Medical Center; associate professor at Cedars-Sinai Medical Center and the David Geffen School of Medicine at UCLA, told Endocrine Today.

The researchers conducted the case-control study examining the metabolic changes (ie, lean body mass, body fat mass, body fat percentage, skeletal muscle mass, BMI and basal metabolic rate) in 128 patients with PCOS (mean age, 28.1 years) and 72 eumenorrheic, non-hirsute controls (mean age, 32.9 years).

In terms of hormonal profile, patients with PCOS had greater testosterone, dehydroepiandrosterone sulfate (DHEA-sulfate), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels compared with controls.

After controlling for age and BMI differences, there was no difference in body composition parameters between patients with PCOS and controls. There were no significant results regarding changes to the basal metabolic rate (P=.0162), lean body mass (P=.0153) or skeletal muscle mass (P=.0169), she said.

However, differences in fasting insulin and HOMA-IR remained significant. When looking at insulin resistance in women with PCOS as a potential factor affecting body composition and metabolic rates, there was also no difference between these groups.

“It is not necessarily PCOS; BMI and age are probably the more important determinants of basal metabolic rate, regardless of PCOS phenotype and insulin resistance,” Pisarska said.