Clinical profile and lipid abnormalities in subclinical and overt primary hypothyroidism

Abstract

Background: Overt and subclinical hypothyroidism, affects metabolism of lipids particularly that of cholesterol, low density lipoprotein and triglyceride. Hypercholesterolemia predisposes to atherosclerosis and thereby increases cardiovascular risks.Methods: Hundred patients of primary hypothyroidism of age more than 15 yrs were included. Five milliliters of venous blood was drawn in fasting state and serum obtained; thyroid function test (TFT) and fasting lipid profile were performed. Based on the TFT, patients were categorized as sub clinical or overt hypothyroidism. Clinical data, thyroid and lipid profiles obtained were analyzed and compared using statistical methods.Results: Seventy patients were females and thirty were males in the ratio of 2.3:1. Most common age group was 51-60years followed by 41-50years. Most common symptom was generalised weakness followed by weight gain, cold intolerance, constipation, hair loss, paraesthesia’s. Most common signs were myxoedema, delayed ankle reflex relaxation, dry and coarse skin, bradycardia, non-pitting peripheral edema, madarosis, pallor, goiter. Patients with Overt hypothyroidism had significantly higher serum levels of total cholesterol(249.1±31.7 mg/dl), Triglycerides (191.5±68.5 mg/dl) and LDL cholesterol(167.7±31 mg/dl) than the Subclinical hypothyroidism with total cholesterol(202±19.8),triglycerides(155.6±35) and LDL cholesterol(129±21.1) but HDL cholesterol level remains normal in both overt (44.0±4.7) and subclinical (43.1±4.4)hypothyroidism respectively.Conclusions: Patients with Overt hypothyroidism had significantly higher levels of Total cholesterol, Triglycerides (TG) and LDL cholesterol than the Subclinical hypothyroidism but HDL cholesterol level remains normal in both. So, concomitant estimation of lipid profile in hypothyroidism patients is needed for early intervention and prevention of cardiovascular morbidity and mortality.

Effect of Hypovitaminosis D on Lipid Profile in Hypothyroid Patients in Saudi Arabia

“…The levels of total cholesterol, triglyceride, and LDL-C were higher in the hypothyroid patients which might be due to inhibition of hepatic low-density lipoprotein (LDL) receptors and cholesterol alpha-monooxygenase activity, resulting in decreased clearance of LDL and total cholesterol [ 26 ]. Similar dyslipidemia patterns have recently been reported in conjunction with the current research [ 27 , 28 ]. The decrease in clearance of LDL and total cholesterol in hypothyroid patients might be due to binding of T3 with the sterol regulatory element binding proteins (SREBP), which upregulate the synthesis of LDL receptors along with the regulatory enzymes of cholesterol synthesis, i.e., hydroxymethyl glutaryl CoA (HMG CoA).…”