A study on lipid profile in sub clinical hypothyroidism of patients attending a tertiary care hospital

Abstract

Subclinical hypothyroidism is also known as mild hypothyroidism, early thyroid failure, preclinical hypothyroidism and decreased thyroid reserve. Subclinical hypothyroidism is defined as a high serum thyroid-stimulating hormone concentration and normal serum total or free thyroxine and triiodothyronine concentrations associated with few or no symptoms and signs of hypothyroidism  and thus subclinical hypothyroid disease is diagnosed by laboratory findings.  Subclinical hypothyroidism is far more common than overt hypothyroidism. The prevalence of subclinical hypothyroidism is relatively high and ranges from 4%-8.5% and maybe as high as 20% in women older than 60 years. Subclinical hypothyroidism is more common in elderly women than men. It is found twice as often in women as in men. Thyroid hormones have a known effect on heart rate & cardiac excitability. Cardio vascular system is the major system affected by subclinical hypothyroidism. Subclinical hypothyroidism patients have an increased risk of “atherosclerosis” & coronary artery disease. Subclinical hypothyroidism patients will have an increased level of total cholesterol, triglyceride, low-density lipoprotein and decreased level of high-density lipoprotein, leading to “atherosclerosis”.  Among the 110 human subjects, 55 were Euthyroid controls and 55 were subclinical hypothyroid cases. Serum total cholesterol, serum triglycerides, serum low-density lipoproteins, levels were increased in subclinical hypothyroid cases than Euthyroid controls with a high statistical significance with the P-value <0.001 and serum high-density lipoproteins levels are decreased in subclinical hypothyroid cases than Euthyroid controls with a high statistical significance with the P-value <0.001. Hence, it should be made mandatory that the estimation of lipid profile should be made as a routine investigation in all cases of subclinical hypothyroidism.