Abstract

No available data exists about the relation of adropin and irisin levels and body weight in hypothyroidism. This work was designed to investigate the relationship between irisin and adropin levels and thyroid hormones. 40 male rats were divided into 2 groups: Control (C) group (10 rats) and hypothyroid group (30 rats). After induction of hypothyroidism, 18 rats increased in body weight (Hypothyroid overweight HO) and 12 rats did not show any significant weight gain (hypothyroid with normal body weight) (HNBW). Body mass index (BMI), adropin, irisin, T3, T4, and TSH were measured. Total cholesterol (TC), triglycerides (TG), serum HDL and LDL levels were estimated. Significant reductions were found in adropin and irisin levels in HO group compared with C and HNBW groups (p<0.001). T3 and T4 were significantly reduced in HO and HNBW groups compared with C group (p<0.001). Significant negative correlations were found between adropin, irisin levels (r=- 0.7967** and -0.7944, respectively) and BMI. Significant (p < 0.01) positive correlations were found between adropin (r=0.7095), irisin (r=0.711) and T3. Significant (p < 0.01) negative correlations were found between adropin and VLDL, TG, TC and LDL (r= -0.968, -0.966, -0.953 and -0.945, respectively) and positively correlated with HDL (r=0.415). Also, irisin was found to be negatively correlated with TG, TC, LDL and VLDL (r=-0.9251, -0.8579, -0.9688 and -0.9769, respectively) and positively correlated with HDL (r=0.5526). Reductions in adropin and irisin levels might be a part of overweight production observed in hypothyroidism.

Key words: Adropin, hypothyroidism, body mass index, irisin, weight gain.