Background: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in young women and increases risk of cardiovascular and metabolic disease, and infertility. Women with PCOS share many characteristics commonly associated with aging including chronic inflammation and insulin resistance, which may be associated with "sarcopenic obesity", a term used to describe low appendicular skeletal muscle mass relative to total body mass. The purpose of this work was to determine the prevalence of sarcopenic obesity in women with PCOS. We hypothesized there would be a high prevalence of sarcopenic obesity, and that % appendicular skeletal muscle mass and markers of inflammation and insulin resistance would be inversely correlated in this population.
Methods: Dual energy X-ray absorptiometry was used to assess body composition in 68 women with PCOS aged 18-35y and 60 healthy age-matched women from the same geographic area. Sarcopenic obesity was defined as having % appendicular skeletal muscle mass 2 standard deviations below the mean for the healthy age-matched controls and a % body fat above 35%. Data were analyzed with Mann-Whitney U-tests and Spearman correlations.
Results: 53% of women with PCOS were classified as sarcopenic obese. Women with PCOS had a median (interquartile range) appendicular skeletal muscle mass of 23.8 (22.3-25.8)% which was lower than the control median of 30.4 (28.6-32.4)% (p < 0.0001). Among women with PCOS, there were negative correlations between % appendicular skeletal muscle mass and the homeostasis model assessment insulin resistance index (r = - 0.409; p < 0.01), high sensitivity C-reactive protein (r = - 0.608; p < 0.0001) and glycosylated hemoglobin (r = - 0.430; p < 0.0001). Furthermore, % appendicular skeletal muscle mass correlated positively with vitamin D (r = 0.398; p < 0.0001) in women with PCOS, which is thought to positively affect skeletal muscle mass.
Conclusions: Women with PCOS have a high prevalence of sarcopenic obesity, which is correlated to insulin resistance and inflammation.
Keywords: Inflammation; Insulin resistance; Muscle; Vitamin D.