Objective: Irisin is a myokine that greatly affects energy expenditure and systemic metabolism. While thyroid hormone is likely associated with irisin, a direct relationship remains to be fully elucidated. This study aimed to investigate plasma irisin levels in Chinese patients with hypothyroidism.
Methods: A total of 155 subjects were divided into the hypothyroidism group or the control group. Fifty-seven patients in the hypothyroidism group received levothyroxine treatment. Baseline irisin levels were measured in the two groups and post-treatment levels were measured in the hypothyroidism group.
Results: Irisin levels were significantly lower in the hypothyroidism group than in the control group. In the hypothyroidism group, irisin levels were positively associated with free triiodothyronine and free thyroxine levels, and negatively associated with thyrotropin levels. In the hypothyroidism group, irisin levels were significantly increased after levothyroxine treatment. Multiple linear regression models showed that total cholesterol and free thyroxine levels were the only significant predictors of serum irisin levels.
Conclusions: Irisin levels are decreased in patients with hypothyroidism. Our results suggest that decreased irisin levels are directly associated with reduced thyroid hormone levels. These values may be restored after levothyroxine treatment in Chinese patients with hypothyroidism.
Keywords: Irisin; creatine kinase; hypothyroidism; levothyroxine; myokine; thyroid hormone.