DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more



Metabolic effects of liothyronine therapy in hypothyroidism: a randomized, double-blind, crossover trial of liothyronine versus levothyroxine.

Author(s): Celi FS, Zemskova M, Linderman JD, Smith S, Drinkard B, Sachdev V, Skarulis MC, Kozlosky M, Csako G, Costello R, Pucino F.

Affiliation(s): Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10, CRC, Room 6-3940, 10 Center Drive, MSC 1613, Bethesda, Maryland 20892-1613, USA. fc93a@nih.gov

Publication date & source: 2011, J Clin Endocrinol Metab. , 96(11):3466-74

CONTEXT: Levothyroxine (L-T(4)) therapy is based on the assumption that the conversion of T(4) into T(3) provides adequate amounts of active hormone at target tissues. However, in rodents, L-T(4) alone does not restore a euthyroid state in all tissues. Previous combination L-T(4)/liothyronine (L-T(3)) therapy trials focused on quality-of-life endpoints, and limited information is available on the effects on other measures of thyroid hormone action. OBJECTIVE: Our objective was to evaluate the efficacy of thyroid hormone replacement with L-T(4) or L-T(3) at doses producing equivalent normalization of TSH. PARTICIPANTS, DESIGN, AND SETTING: Fourteen hypothyroid patients participated in this randomized, double-blind, crossover intervention at the National Institutes of Health Clinical Center. INTERVENTIONS: L-T(3) or L-T(4) were administered thrice daily to achieve a target TSH from 0.5-1.5 mU/liter. Volunteers were studied as inpatients after 6 wk on a stable dose and at the target TSH. MAIN OUTCOME MEASURES: Serum thyroid hormones, lipid parameters, and indices of glucose metabolism were evaluated. RESULTS: No difference was observed in TSH between L-T(3) and L-T(4) treatments. L-T(3) resulted in significant weight loss [L-T(4), 70.6 ± 12.5, vs. L-T(3), 68.5 ± 11.9 kg (P = 0.009)] and in a 10.9 ± 10.0% decrease in total cholesterol (P = 0.002), 13.3 ± 12.1% decrease in low-density lipoprotein-cholesterol (P = 0.002), and an 18.3 ± 28.6% decrease in apolipoprotein B (P = 0.018). No significant differences were observed in high-density lipoprotein-cholesterol, heart rate, blood pressure, exercise tolerance, or insulin sensitivity. CONCLUSIONS: The substitution of L-T(3) for L-T(4) at equivalent doses (relative to the pituitary) reduced body weight and resulted in greater thyroid hormone action on the lipid metabolism, without detected differences in cardiovascular function or insulin sensitivity.

Page last updated: 2013-02-10

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017