Correlation Of Thyroid Stimulating Hormone With Polycystic Ovarian Syndrome

Abstract

Polycystic Ovarian Syndrome (PCOS) is a complex endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and metabolic disturbances. While the roles of insulin resistance and obesity are well-documented, the influence of thyroid function specifically within the subclinical and high-normal range on the severity of PCOS remains a subject of clinical debate, particularly in the South Asian demographic. The primary objective of this study was to find out the correlation between Thyroid Stimulating Hormone (TSH) levels and the clinical, hormonal, and metabolic profile of PCOS. A cross-sectional study was conducted involving 138 female patients diagnosed with PCOS according to the Rotterdam Criteria at clinical centers in Lahore. Anthropometric measurements and biochemical profiles, including TSH, Total Testosterone, Anti-Müllerian Hormone (AMH), and the LH/FSH ratio, were recorded. Insulin resistance was assessed using the HOMA-IR index. Statistical analysis was performed using Pearson correlation test, Independent Samples T-Tests to compare euthyroid and high-TSH groups, and Linear Regression to identify independent predictors of hyperandrogenism. The study revealed a high prevalence of subclinical thyroid dysfunction, with nearly 70% of participants exceeding a TSH level of 2.5 mIU/L. Significant positive correlations were found between TSH and HOMA-IR (r = 0.91, p < 0.001), Total Testosterone (r = 0.85, p < 0.001), and AMH (r = 0.79, p < 0.01). Comparative analysis showed that patients with TSH > 2.5 mIU/L exhibited significantly higher testosterone (95.8 vs 42.5 ng/dL) and insulin resistance (92% vs 18%) than euthyroid patients. Regression analysis confirmed TSH as the strongest independent predictor of testosterone levels (beta = 0.68, p < 0.001), outweighing the influence of BMI. TSH is a critical modulator of the PCOS phenotype, where even minor elevations within the high-normal range exacerbate hormonal and metabolic severity. Clinical management of PCOS should prioritize a more stringent TSH threshold of 2.5 mIU/L.