MON-205 Is Muscle Mechanical Function Altered In Polycystic Ovary Syndrome?

Abstract

Context: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of women of reproductive age, characterized by androgen excess, ovulatory dysfunction and polycystic ovaries (PCOM). Limited and conflicting data are available regarding musculoskeletal system and muscle strength in PCOS. Objective: The aim of the current study was to assess muscle mechanical function in PCOS and its relation with hormonal and metabolic features of the syndrome. Design: The study included 44 women with PCOS, all having clinical or biochemical hyperandrogenism, chronic oligo-anovulation and PCOM (2003 Rotterdam criteria – phenotype A), and 32 age- and BMI-matched healthy women. Anthropometric, hormonal and biochemical measurements were performed in all participants. Muscle mechanical function including lower limb explosive strength and average power was measured by using isokinetic dynamometry, a valid and reliable instrument for measuring muscle strength. Results: The mean age and BMI of the women with PCOS and healthy controls were 21.8+3.2 versus 22.8+3 years and 26.1+5.4 versus 25.5+5.7 kg/m2 respectively (p=NS for both). PCOS patients had higher modified Ferriman-Gallwey (mFG) scores and higher levels of bioavailable testosterone (bT) than controls (p<0.05 for both), whereas fasting glucose and fasting insulin levels were similar between the groups. Isokinetic measurement of quadriceps and hamstring strength were performed by Biodex 3 dynamometer at an angular velocity of 60°/s. The peak muscle force output during the assessment was defined as the peak torque (PTQ) and was reported as body weight-normalized (Nm/kg) PTQ. Average power (AvP) was determined by the time-averaged integrated area under the curve at 60°/s angular velocity. The normalized values of knee extensor and flexor PTQ at 60°/s were similar between patients and controls whereas these values were higher in normal weight individuals compared to overweight-obese individuals (p<0.05 for both). The AvP at 60°/s with extension and flexion was significantly higher in PCOS group (50.3+21.2 vs 42.1+11.6 and 35.3+27 vs 22.2+11.1 respectively, p <0.05 for both). These measurements were correlated with bT (r=0.29, p=0.012, r=0.36, p=0.001 respectively). Conclusion: Muscle mechanical function is altered in PCOS. Women with PCOS have increased average lower limb power that is associated with hyperandrogenism.