Total cholesterol/high density lipoprotein-cholesterol ratio as an indicator of Dyslipidemia in hypothyroidism

Abstract

Background: The thyroid hormones are involved in controlling metabolism, growth and functions of various organ systems of our body. Hypothyroidism, a very common endocrinopathy features reduced production of thyroid hormones. In hypothyroidism we encounter abnormal circulating lipid fractions which is termed as ‘Dyslipidemia’. The coexistence of dyslipidemia and hypothyroidism is associated with development of atherosclerosis. Aim: This research is undertaken to assess the potential of TC/HDL-C ratio to disclose dyslipidemia in hypothyroidism. Methodology: The study consists of two major groups, the ‘Cases’ comprising of Fifty hypothyroid patients and ‘Controls’, with fifty age and gender matched healthy adults. The Cases are further subdivided into Twenty ‘Known cases’ of Hypothyroid patients, already receiving treatment and thirty ‘New cases’. The ‘New cases’ sub group further is subdivided as Twenty-one ‘Overt hypothyroids’(OH) and nine ‘Subclinical Hypothyroids’ (SCH). The Biochemical parameters estimated in all subjects of the study includes, Serum TSH, T3, T4, Total Cholesterol (TC) and High density lipoprotein-cholesterol(HDL-C). TC/HDL ratio was then calculated . Result: The study shows a significant elevation (p = 0.05) in the TC/HDL-C ratio in hypothyroid patients (3.67 ± 1.02) when compared to healthy controls (3.29 ± 0.95). TC/HDL-C ratio is more elevated in OH (4.01 ± 1.28) than in SCH (3.46 ± 0.92). The levels in ‘New cases’ sub-group and OH sub sub group have significantly higher ratio than in healthy controls (p = 0.02 and p = 0.01 respectively). TC/HDL-C ratio value in “known cases’ group who are those hypothyroid patients on Levo-thyroxine therapy is (3.40 ± 0.61) less than those who are newly diagnosed. Conclusion: TC/HDL-C ratio is not only raised in hypothyroid patients but it is seen increasing with severity and prolonged duration of disease. The calculation of TC/HDL-C ratio should be routinely put into practice to detect hypothyroid patients with dyslipidemia.