The Relationship between serum levels of Thyroid Hormones (T3, T4) Thyroid-Stimulating Hormone (TSH) and Serum Lipid Profile

Background: The correlation between blood levels of Thyroid hormones with lipid metabolism still seems controversial. Some studies have shown the relationship between low levels of T3 with cardiovascular diseases. This study was conducted in order to examine the relationship between Thyroid hormones (T3, T4), Thyroid-Stimulating Hormone (TSH) and the level of serum lipids as a risk factor of cardiovascular diseases.

Methods: The data were collected from the medical examination results in the records and medical history of the 200 individuals who, during 2010 and early 2011, did thyroid hormones and serum lipids (cholesterol, triacyglycerol, HDL, LDL, and VLDL) tests simultaneously. The data later were analyzed using ANOVA and Pearson correlation tests by SPSS 16 software.

Results: The sample included 200 patients with average age of 38.29±14.408 years old of which, 59 (29.5%) were males with average age of 39.05±16.663 and 141 (70.5%) were females with average age of 37.97±13.406. The results indicated that both Triglyceride (P=0.01) and, VLDL (P=0.05) are negatively correlated with T4. Also, a negative correlation was found between serum T4 level and cholesterol in male subjects (P=0.06).  Moreover, a negative correlation was observed between T4 and VLDL in female subjects (P=0.046). In addition, the levels of HDL-C in female subjects were more than in male subjects (P<0.001).

Conclusion: to conclude, it was found that VLDL, triglyceride, cholesterol in men, and VLDL in women are negatively correlated with serum T4 level.