Correlation Between Serum TSH Levels Within Normal Range and Serum Lipid Profile.

Abstract

The aim of the work was to investigate the correlation between serum TSH (thyrotropin) levels within normal range and serum lipids. A total of 1962 subjects with normal thyroid function were enrolled. The subjects were divided into four groups according to the quartiles of serum normal TSH levels, [Q1 (0.27-1.68) mIU/l, Q2 (1.69-2.35) mIU/l, Q3 (2.36-3.07) mIU/l, and Q4 (3.08-4.20) mIU/l]. The effect of serum normal TSH levels on serum lipid profiles of different age or gender was analyzed. The total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) levels of the Q3 group and TG levels of the Q4 group were higher than those of the Q1 group in youth (p <0.05). The TC levels of the Q3 group were higher than those of the Q2 group in middle age (p <0.05). The LDL-C levels of middle age or elderly were higher than those of youth at the same TSH levels (p <0.05), while the TC levels of middle age were higher than those of youth in Q1, Q3, or Q4 group (p <0.05), and the TC and HDL-C levels of elderly were higher than those of youth in the Q2 group (p <0.05). The TG levels of the Q3 group were higher than those of Q1 group in males (p <0.05). The LDL-C levels of the Q3 group were higher than those of the Q1 group in females (p <0.05). In conclusion, the normal serum TSH levels were found to be closely related to serum lipid profiles, and with increasing TSH levels, serum lipids levels increased gradually.