The association between TSH within the reference range and serum lipid concentrations in a population-based study. The HUNT Study

Abstract

Objective: The association between TSH and serum lipids in people with no apparent thyroid disease is insufficiently understood. We have studied the association between normal thyroid function, defined as TSH within the reference range of a general population, and concentrations of serum lipids. Design: Cross-sectional, population-based study with 30 656 individuals without known thyroid disease. Methods: Using general linear models, we calculated mean concentrations of total serum cholesterol, low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (HDL) cholesterol, HDL cholesterol and triglycerides across categories of TSH. Results: Within the reference range of TSH, there was a linear and significant (P for trend P for trend Conclusions: Within the range of TSH that is considered clinically normal, we found that increasing level of TSH was associated with less favourable lipid concentrations. The association with serum lipids was linear across the entire reference range of TSH.