Introduction: The relationship between thyroid hormones and lipids has long been studied, having been first described more than 70 years ago. Since then, much new information has been discovered, which justifies a reevaluation of the relationship between thyroid pathology and dyslipidemia. Thyroid hormones play an important role in regulating lipid metabolism, and thyroid dysfunction can result in lipid abnormalities which increase the risk of endothelial dysfunction, hypertension and cardiovascular disease.
Methodology: A review of the literature was carried out on the association between thyroid diseases, lipid profile and cardiovascular risk, using the Medline database and textbooks. Articles in English and Portuguese published between 1980 and 2007 were selected. Data collection took place between 2003 and 2007.
Results: The increased cardiovascular risk in thyroid dysfunction is related to lipid profile, endothelial dysfunction, metabolic, hormonal and hemodynamic changes and coagulation disturbances. Because of its high prevalence in the population hypothyroidism is the principal functional disorder. Lipid anomalies associated with hypothyroidism are at least partially responsible for the increase in coronary heart disease.
Conclusion: The clinical benefit of treating subclinical hyperthyroidism is still the subject of debate, but treatment appears to be associated with beneficial effects on lipi d profile and cardiovascular function. Further studies are required to clarify the influence of various degrees of thyroid dysfunction in the development of atherosclerosis and cardiovascular morbidity.