Abstract: Objective To analyze the effect of subclinical hypothyroidism(SCH)on endocrine and metabolic characteristics of polycystic ovary syndrome(PCOS)patients, and to explore the correlation between thyroid stimulating hormone (TSH) level and various endocrine and metabolic indexes. Methods Totally 661 patients with PCOS in the outpatient Department of Endocrinology and Metabolism of the First People's Hospital of Yunnan Province from January 2020 to June 2021 were selected as the research object. The general data and related endocrine and metabolic indexes of the patients were collected. Taking the TSH value of 4.2 mIU/L as the cut-off point for the diagnosis of SCH, PCOS patients were divided into SCH group and non SCH group. The differences of endocrine and metabolic characteristics between the two groups were compared; The correlation between TSH level and its endocrine and metabolic indexes was analyzed. Results The incidence of SCH in PCOS patients was 31.16%. Compared with PCOS patients without SCH, the levels of TSH, prolactin and triglyceride in the group with SCH were significantly higher, and the levels of free thyroxin and estradiol were significantly lower (P＜0.05). TSH level was negatively correlated with free thyroxin in PCOS patients (r=-0.152, P＜0.001), and positively correlated with total cholesterol and triglycerides (r=0.133, 0.111, P＜0.01,P＜0.05, respectively). Conclusions PCOS patients with SCH have more serious endocrine hormone disorders and dyslipidemia, which may further aggravate the risk of cardiovascular diseases and reproductive abnormalities in PCOS patients. It is suggested that patients with PCOS should be screened for thyroid function and lipid metabolism regularly and followed up for a long time.

Key words: polycystic ovary syndrome, subclinical hypothyroidism, thyroid stimulating hormone, abnormal lipid metabolism, insulin resistance