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.