Basal metabolic rate in women with PCOS compared to eumenorrheic controls.

Objective: PCOS is associated with obesity and insulin resistance. Efforts have focused on whether an abnormal energy homeostasis contributes to the development of obesity in these patients. There are conflicting results in the literature regarding whether women with PCOS have an altered basal metabolic rate (BMR), thereby leading to difficulties in weight loss. The objective of this study is to compare basal metabolic rate (BMR) in women with PCOS and controls.

Design: Cross-sectional study.

Patients: One hundred and twenty-eight PCOS patients diagnosed by original NIH consensus criteria and 72 eumenorrheic, non-hirsute controls were recruited from an academic medical centre.

Measurements: Assessment of BMR using the InBody portable bioelectrical impedance analysis (BIA) device and insulin resistance by HOMA-IR indices.

Results: PCOS women were younger than controls. As expected, PCOS subjects had higher body mass index (BMI), serum androgens and estimated insulin resistance. After adjusting for age and BMI, there was no significant difference in BMR between PCOS subjects (adjusted mean 5807 kJ/day, 95% CI 5715-5899) and controls (adjusted mean 5916 kJ/day, 95% CI 5786-6046) (P = 0·193). BMR was also comparable in a secondary analysis comparing PCOS women with and without insulin resistance.

Conclusions: After adjusting for age and BMI, there was no difference in BMR between PCOS women and controls.