Endocrine Abstracts

Background and Aim: Polycystic ovary syndrome (PCOS) is characterized by androgen excess and ovulatory dysfunction and appears to be associated with alterations in muscle mass and function. Combined oral contraceptives are commonly used for the long-term management of PCOS and their potential impact on muscle mass and strength remains unknown. This study aimed to assess whether oral contraceptive (OC) use along with general lifestyle advice would alter muscle mass and strength in women with PCOS.

Methods: Twenty women with PCOS (median age and BMI: 20.5 years and 26.1 kg/m²respectively) and 20 age- and BMI-matched healthy controls were included. Following clinical, hormonal and biochemical assessments, body composition analyses were performed by magnetic resonance imaging (MRI) proton density fat fraction (PDFF%). Muscular strength parameters including lower limb extensor/flexor torque, total work and average power (AvP) were obtained by isokinetic dynamometry, gold standard for assessment of muscle strength. Measurements were made for all participants at baseline and repeated after OC use in women with PCOS.

Results: Women with PCOS at baseline had higher levels oftotal testosterone, free androgen index (FAI), and homeostasis model assessment of insulin resistance (HOMA-IR) levels compared to healthy women (P<0.001, P=0.001, P=0.004 respectively). The PCOS group showed significantly higher average power (AvP) of knee extensors at 60°/sec compared to controls before initiation of OC therapy (P=0.002), with positive correlations noted between AvP and total testosterone and FAI levels in the whole study group (r=0.45, P=0.004, r=0.318, P=0.045 respectively). The median duration of OC therapy in the PCOS group was 121 days (IQR: 85-149). Testosterone levels and FAI showed significant decline following OC use (P=0.02, P<0.001 respectively). However, these alterations were not associated with any significant change in thigh muscle mass or lower limb strength.

Conclusion: The results of this study suggest that short-term OC use ameloriates androgen excess but does not alter muscle composition or strength in women with PCOS. Further research is needed in PCOS to understand potential effects of long-term management strategies on muscle mass and function.

Keywords: Polycystic ovary syndrome, oral contraceptive, adiposity, body composition, insulin resistance, muscle strength