The polycystic ovary syndrome (PCOS) is not only the first cause of female infertility but also a complex, endocrine, multifaceted disease with important health implications. PCOS is often associated to the metabolic syndrome, and insulin resistance represents the main characteristics for both these syndromes. The metabolic disturbances characteristic of insulin-resistant states have been linked to the role of mitochondrial function and in particular to the maximal oxygen consumption (VO2max).
The aim of this study was to assess functional capacity in PCOS. Thirty PCOS women age- and body mass index-matched with 30 healthy women were enrolled. In each subject the assessment of functional capacity by cardiopulmonary exercise testing was performed, evaluating: VO2max, VO2AT (oxygen consumption at anaerobic threshold), Wattmax (maximal workload at peak exercise). Biochemical and hormonal patterns were evaluated; insulin, glucose, and lipids levels were measured and the Homeostasis Model Assessment of insulin resistance (HOMA-IR) index was also calculated.
VO2max (17.1±2.9 vs. 26.8±3.5 ml/Kg/min, P<0.001), VO2AT (13.7±3.2 vs. 21.4±3.6 ml/Kg/min, P<0.001) and Wattmax (101.3±25.2 vs. 135±22.6 W, P<0.001) resulted significantly reduced in PCOS compared to healthy women. HOMA-IR was significantly increased in PCOS compared to controls (4.6±1.8 vs. 1.3±0.5, P<0.001). There was a significant linear correlation between VO2max and HOMA-IR in PCOS (r=0.70, P<0.001).
In conclusion our data firstly demonstrate a cardiopulmonary impairment with a reduced functional capacity in young PCOS women probably related to insulin resistance. Functional capacity could be a powerful further marker to assess the cardiovascular risk in PCOS.