Abstract
Background: Thyroid gland is one of the most important glands in the human body which responsible for the secretion of Thyroxin (T4) and Triiodothyronine (T3) hormones. These hormones in addition to Thyroid Stimulating Hormone (TSH) have a great effect on other hormones like leptin. So, the objective of this study is to assess any correlation between thyroid hormones, lipid profile, and leptin in female patients with thyroid dysfunction.

Methods: This cross-sectional study was conducted for 50 women diagnosed with hypothyroidism (25) and hyperthyroidism(25) attending AL-Karamah Teaching Hospital in Wasit. All of them ranged between 20-55 years. The researchers obtained verbal consent and then took a serum sample from all of them to test the level of thyroid hormones (T4, T3), TSH, leptin hormone and lipid profile (TG, HDL-C, LDL-C and cholesterol) were determined. Data were analyzed by SPSS version 23 using descriptive statistic for quantitative variables. Independent t-test, correlation and regression analysis were also used.

Results: This study found that both the leptin level and lipid profiles (Cholesterol, TG, LDL and HDL) were significantly higher (P<0.01) in hypothyroid patients relative to hyperthyroid. A significant negative correlation was found between T4, T3 and leptin (P<0.01). The leptin can be significantly mainly predicted by TSH (P<0.001) in female patients with thyroid dysfunction. Also found that there is a strong and significant (P<0.01) correlation between all studied variables with leptin.

Conclusion: Although the leptin hormone level in patients with thyroid dysfunction showed a strong correlation with lipid profiles, TSH, and thyroid gland hormones. The only significant predictor for leptin was the TSH.

Key words: Hypothyroidism, Hyperthyroidism, Leptin, Lipid Profile, TSH.