The Effects of Dyslipidemia in Subclinical Hypothyroidism

Background Subclinical hypothyroidism (SCH) affects 7.5-8.5% of women and 2.8-4.4% of men globally. Usually, both hypothyroidism and hyperthyroidism are related to cardiovascular and cerebrovascular disease development. The relationship between subclinical hypothyroidism and dyslipidemia has been widely investigated, but the findings remain controversial. Recent evidence shows that serum thyroxine (T4) replacement therapy may improve lipid profiles. The objective of the present study is to assess dyslipidemia among patients with SCH in Benghazi, Libya and compare it with controls. Methods The study was conducted from August 2018 to November 2018 and included 36 patients with SCH. All the patients were around 30 years of age. We also included sex-matched healthy subjects (controls) selected from three diabetes and endocrinology clinics in Benghazi: Alhaya clinic, Alrazy clinic, and Alnukbah clinic. Clinical information and medical history were obtained through a questionnaire from all SCH patients and normal control subjects. Blood samples were collected and analyzed for thyroid-stimulating hormone (TSH), free thyroxine (FT4), total cholesterol (T-Chol), serum triglycerides (STG), low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C). Results Patients with SCH showed significantly higher T-Chol, STG, and LDL-C levels, as well as significantly lower levels of HDL-C in comparison to the healthy controls. No significant correlation was found between TSH and T-Chol, STG, HDL-C, and LDL-C; no significant correlation was found between FT4 and HDL-C either. However, a strong negative correlation was found between FT4 and T-Chol, STG, and LDL-C. Conclusion Our study concluded that SCH is associated with dyslipidemia. We strongly recommend biochemical screening for thyroid dysfunction for all patients with dyslipidemia.