Lipid Profile and Thyroid Hormones in Types 1 and 2 Diabetics

Abstract

Literature describing relationship between thyroid hormones and lipid levels in Types 1 and 2 diabetics is scanty. Medications used in treating each of the two classes of diabetes differ and the effect of the various hypoglycemic agents on thyroid hormones varies, while thyroid hormone levels relate inversely with cholesterol levels. We measured thyroid hormones and lipids levels in 18 Type 1 and 143 Type 2 diabetics using Enzyme immunoassay reagent kits manufactured by Biomerica Inc., Newport Beach, California, USA and Biolabo, Fines, France, respectively. The Triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) were significantly higher in Type 1 than in Type 2 diabetics (p = 0.025, 0.002, respectively), but very low-density lipoprotein cholesterol (VLDL-C) was higher (p = 0.027) in Type 2 than in Type 1 diabetics. Free thyroxine (FT4) showed significant positive correlation with total cholesterol (TC) (r = 0.179, p = 0.034), HDL-C (r = 0.176, p = 0.037) and VLDL-C (r =.183, p =.030) in Type 2, but not in type 1 diabetics. Total triiodothyronine (T3) and TG were positively correlated in Type 1 diabetics, (r =0 .59, p 0.027) but were not correlated in Type 2 subjects. T3 and VLDLC levels showed positive correlation in Type 2 diabetics (r = .224, p = 0.003), but were not correlated in Type 1 subjects. The relationship between thyroid hormones and lipid profile differ in Type 1 and Type 2 diabetics, as the levels of LDL-C, VLDL-C triglycerides, HDL-C and thyroid hormones varied in magnitude and direction of association in the 2 classes of diabetes mellitus subjects. Both the classes of diabetes mellitus and the levels of thyroid hormone do influence lipid levels in diabetics differently.