Background: Abnormalities in plasma lipids are most frequently the result of the interaction between the individual and the environment; therefore, it is essential to look for secondary causes in all patients with dyslipidemia.
Aim: To describe the pathogenesis of dyslipidemia and in particular the role of hypothyroidism as a secondary dyslipidemia.
Main data: Overt hypothyroidism (OH) is associated to impairment of the lipid profile both quantitatively and qualitatively. Subclinical hypothyroidism (5CH) has been also related to lipid derangement albeit with milder impact. Moreover, the association between low thyroid function and lipid plasma levels has been also found to extend into the normal range of TSH. However, confounders such as age, gender and body weight may modify this association. The effects of treatment with levothyroxine for cholesterol reduction are warranted in OH while in SCH, larger interventional studies on lipid reduction with levothyroxine are lacking.
Conclusion: Hypothyroidism should always be considered in the evaluation of patients with dyslipidemia.