Plasma Lipoprotein Alterations in Thyroid Dysfunction

Changes in plasma lipid concentrations are well known metabolic consequences of thyroid dysfunction. The alterations are most prominent in hypothyroidism which is typically associated with pronounced hypercholesterolemia and frequently also with moderate hypertriglyceridemia. Hyperthyroidism, on the other hand, is often accompanied by decreased levels of serum cholesterol. Although the pathophysiological mechanisms for these lipoprotein abnormalities are not clarified, it is well known that these changes are completely reversible. Since thyroid disease is rarely associated with secondary alterations in other organs involved in plasma lipoprotein metabolism, patients with thyroid dysfunction provide an unusually clean model for dynamic studies on the regulation of lipoprotein metabolism in man. The present investigations focus on the relationships between thyroid hormones and key enzymes in lipoprotein metabolism, and on the impact of enzyme alterations on the plasma lipoprotein profile. Besides improving our understanding of the pathogenesis of the dyslipoproteinemias in thyroid dysfunction per se, such information