Lipid Profile in Subclinical Hypothyroidism: A Case-control Study
Abstract
Subclinical Hypothyroidism is a much more common disorder with a world-wide occurrence as compared to overt Hypothyroidism. Overt Hypothyroidism is associated with abnormalities of lipid metabolism, but the significance of dyslipidemia in subclinical hypothyroidism (SCH) remains controversial.
Aims: To compare the lipid profile between subclinical hypothyroid patients & healthy controls (age & sex matched) so as to determine any association between lipid profile & subclinical hypothyroidism.
Materials and Methods: In a case-control study, Thyroid stimulating hormone (TSH), free T3, free T4, anti thyroperoxidase (TPO) antibodies, total cholesterol, high density lipoprotein(HDL) cholesterol, low density lipoprotein (LDL) cholesterol, Very low density lipoprotein (VLDL) cholesterol, serum triglycerides were measured in 50 patients with subclinical hypothyroidism and 50 age- and sexmatched Euthyroid controls after an overnight fasting.
Results: Mean serum triglycerides (TG) and very low-density cholesterol (VLDL) were significantly higher in patients with SCH than controls (P < 0.05). No association was found between serum total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and SCH.
Conclusions: Dyslipidemia is more common in SCH compared to controls. High serum triglycerides and VLDL were observed in patients with SCH
Keywords
Download Options
Introduction
Subclinical hypothyroidism (SCH) can be best defined as a high serum thyroid stimulating hormone (TSH) and normal serum total/free thyroxine (T4), triiodothyronine (T3) concentrations associated with few or no symptoms/signs of hypothyroidism. It is referred to as a state of mild thyroid failure and is essentially a laboratory diagnosis.1,2 Subclinical hypothyroidism is much more common than overt hypothyroidism3,4 with a world-wide prevalence of about 7.5% to 8.5% in women and 2.8% to 4.4% in men. 5
Thyroid hormones have significant effects on the synthesis, mobilization and metabolism of lipids. They affect serum cholesterol mainly by altering lipoprotein metabolism. A relationship between dyslipidemia and atherosclerosis is well established in overt hypothyroidism.
Conclusion
It can be concluded from present study that subjects with laboratory finding of hypertriglyceridemia should be further examined and tested for serum thyroid profile and particularly thyroid stimulating hormone (TSH) should be assessed carefully. Early diagnosis and treatment of such patients may prevent the onset of overt hypothyroidism and its associated complications. Further studies are required to support the significance of early thyroid evaluation and its treatment.