Endocrine Abstracts

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects reproductive age women and predispose to the development of metabolic disturbances. However, Rotterdam criteria, commonly used to diagnose and classify this disorder, do not include metabolic markers. Recent research has shown that several metabolic factors may play a role in PCOS pathogenesis. Branched-chain amino acids (BCAA) are the group of essential amino acids including leucine, isoleucine and valine and studies have shown that PCOS women have higher levels of BCAA compared to healthy individuals. LAP (lipid accumulation product) is an index combining waist circumference and triglycerides concentration that was found to be helpful in recognizing insulin resistance and predicting liver steatosis.

Methods: A group of 326 women: 209 diagnosed with PCOS and 117 healthy individuals, was included in the study. Multiple parameters were assessed, including anthropometrical, biochemical and hormonal ones; HOMA-IR and LAP were calculated using known formulas. The gas–liquid chromatography combined with tandem mass spectrometry was used to investigate BCAA level. PCOS women were grouped using Rotterdam criteria into four main phenotypes, which included: A-46, B-92, C-43 and D-28 individuals. Additionally, from the PCOS group, 46 women diagnosed with obesity were separated for further analysis. Subsequently, obese PCOS patients were classified as Metabolically Healthy (MHO) and Metabolically Unhealthy Obesity (MUO); these subgroups consisted of 27 and 19 age-matched individuals, respectively.

Results: Statistical analysis of metabolic parameters showed significant differences in BMI, HOMA-IR and total cholesterol level between PCOS phenotypes; however, fasting glucose, HDL, triglycerides, valine, leucine and isoleucine concentrations, as well as LAP do not differ in these subgroups. Comparison of MHO and MUO PCOS women, revealed that LAP, leucine and isoleucine concentrations were significantly higher among MUO subgroup: 101.98±34.74 vs 55.80±24.33 (P<0.001); 153.26±22.26 vs 137.25±25.76 nmol/ml (P=0.04) and 92.92±16.09 vs 82.60±18.70 nmol/ml (P=0.02), respectively. No significant differences in BMI, fasting glucose and HOMA-IR between MHO and MUO were found: 35.0±4.8 vs 36.1±4.6 kg/m2 (P=0.59); 88.0±6.0 vs 87.73±6.28 mg/dl (P=0.67); 3.36±1.70 vs 4.17±1.77 (P=0.1), respectively.

Conclusions: PCOS phenotypes distinguished with Rotterdam criteria represent the differences between patients according to ovulatory and androgen excess symptoms. However, to better identify patients at risk of metabolic disorders, a new classification is needed. Leucine and isoleucine concentrations, as well as lipid accumulation product, should be taken into consideration as metabolic factors that might be included in PCOS classification since they are helpful in differentiation of ‘metabolic health’.