Subclinical hypothyroidism in patients with polycystic ovary syndrome: distribution and its association with lipid profiles.

The aim of this study was to examine the distribution of subclinical hypothyroidism (SCH) in patients with polycystic ovary syndrome (PCOS). We also aimed to investigate the associations between thyroid stimulating hormone (TSH) and lipid profiles and to determine the values at which TSH levels affected dyslipidemia risk in this population.Women with PCOS (n=428) from a Chinese Han population were recruited and stratified into five groups based on TSH levels. Multiple linear regression analysis was performed to investigate the associations between serum TSH and lipid profiles. Receiver operating characteristic (ROC) analysis was used to find the optimal TSH cut-off point for dyslipidemia risk.The SCH distribution was observed similarly in PCOS patients with different phenotypes (Chi-squares=2.184, P=0.535). There was a significant positive correlation between TSH and low density lipoprotein cholesterol (LDLc) (P=0.001), even after adjustment for age, body mass index, waist to hip ratio, fasting plasma glucose, homeostatic model assessment-insulin resistance and free androgen index (P<0.001). The optimal TSH cut-off point to indicate elevated LDLc risk was 4.07 mIU/L by ROC analysis.Our data indicate that TSH is strongly associated with higher LDLc concentrations in PCOS patients. The optimal TSH cut-off point for elevated LDLc risk in this cohort was 4.07 mIU/L. These findings demonstrate that more attention might be paid to PCOS paients prior to overt clinical presentation.