Effect of Thyroid Hormone Replacement on Lipoprotein(a), Lipids, and Apolipoproteins in Subjects With Hypothyroidism

• Published in: Mayo Clinic proceedings Vol. 73; no. 9; pp. 837 - 841
• Main Authors: Triguero, María L. Martínez, Hernández-Mijares, Antonio, Nguyen, Tu T., Muñoz, Maria L., Peña, Hector, Morillas, Carlos, Lorente, David, Lluch, Irene, Molina, Ernesto
• Format: Journal Article
• Language: English
• Published: Rochester, MN Elsevier Inc 01.09.1998; Mayo Medical Ventures; Elsevier Limited
• Subjects: Apolipoproteins - blood; Biological and medical sciences; Cholesterol - blood; Enzyme-Linked Immunosorbent Assay; Hormones. Endocrine system; Humans; Hypothyroidism - blood; Hypothyroidism - drug therapy; Lipids - blood; Lipoprotein(a) - blood; Medical sciences; Pharmacology. Drug treatments; Thyroxine - therapeutic use; Triglycerides - blood; HDL-C; FT 4; LDL; LDL-C; TSH; apo B; apo A-I; Lp(a); TC; Endocrinopathy; Human; Chemotherapy; Treatment; Follow up study; Treatment efficiency; Thyroid diseases; Thyroid hormone; Lipids; Apolipoproteins; Hypothyroidism; Lipoprotein a
• ISSN: 0025-6196; 1942-5546
• DOI: 10.4065/73.9.837

To study the effect of thyroid hormone replacement on total cholesterol, low-density lipoprotein cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I and B-100, and lipoprotein(a) [Lp(a)] in subjects with hypothyroidism. In 17 patients with clinical primary hypothyroidism, studies were done before and after thyroid hormone replacement therapy. Free thyroxine and thyrotropin were determined by chemiluminescent assay. Total cholesterol and triglycerides were measured by enzymatic methods, and HDL-C was measured after dextran sulfate-MgCl 2, precipitation. Apolipoprotein A-I and B-100 were assayed by immunonephelometry. For measurement of Lp(a), we used a sequential sandwich enzyme-linked immunosorbent assay. After levothyroxine treatment, the mean concentration of thyrotropin decreased from 91.4 to 3.7 μIU/mL, and free thyroxine increased from 0.5 to 1.2 ng/dL. Total cholesterol, triglycerides, HDL-C, low-density lipoprotein cholesterol, and apolipoprotein A-I and B-100 decreased after thyroid hormone replacement therapy. Lp(a) levels also decreased significantly ( P<0.05) after treatment, from a mean of 33.4 to 25.6 mg/dL. Hypothyroidism is associated with an increase in total cholesterol, triglycerides, HDL-C, apolipoprotein A-I and B-I00, and Lp(a). A reduction in lipid and lipoprotein levels after thyroid hormone replacement in our study cohort resulted in a less atherogenic profile.