Objectives: Alteration in lipid profile constitutes an important risk factor for development of cardiovascular diseases. Thyroid status may affect lipid profile and the mechanism of this relationship is traditionally attributed to the influence of thyroid hormone. We have studied the association between TSH outside the reference range and concentrations of serum lipids in a hypothyroid patients and the role of BMI in modulating the association between TSH and lipid parameters. Methods: Using general linear models, we calculated mean concentrations of total serum cholesterol, low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (VLDL) cholesterol, HDL cholesterol and triglycerides across categories of TSH. Results: outside the reference range of TSH, there was a linear and significant (P value< 0.001) increase in total serum cholesterol, LDL cholesterol, VLDL cholesterol and triglycerides, and a linear decrease ((P value < 0.001) in HDL cholesterol with increasing TSH. The associations with triglycerides and HDL cholesterol were stronger among overweight than normal weight individuals. Conclusions: we found that increasing level of TSH was associated with less favourable lipid concentrations. MI mediates the effect of thyroid function on lipid profile in hypothyroid patients.
