L-carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: A randomized, double-blind, placebo-controlled trial

Jee Hyun An, Yoon Jung Kim, Kyeong Jin Kim, Sun Hwa Kim, Nam Hoon Kim, Hee Young Kim, Nan Hee Kim, Kyung Mook Choi, Sei Hyun Baik, Dong Seop Choi, Sin Gon Kim

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

Hypothyroid patients experience fatigue-related symptoms despite adequate thyroid hormone replacement. Thyroid hormone plays an essential role in carnitine-dependent fatty acid import and oxidation. We investigated the effects of L-carnitine supplementation on fatigue in patients with hypothyroidism. In total, 60 patients (age 50.0 ± 9.2 years, 3 males, 57 females) who still experienced fatigue (fatigue severity scale [FSS] score ≥ 36) were given L-carnitine (n = 30, 990 mg L-carnitine twice daily) or placebo (n = 30) for 12 weeks. After 12 weeks, although neither the FSS score nor the physical fatigue score (PFS) changed significantly, the mental fatigue score (MFS) was significantly decreased by treatment with L-carnitine compared with placebo (from 4.5 ± 1.9 to 3.9 ± 1.5 vs. from 4.2 ± 1.8 to 4.6 ± 1.6, respectively; P < 0.01). In the L-carnitine group, 75.0%, 53.6%, and 50.0% of patients showed improvement in the FSS score, PFS, and MFS, respectively, but only 20.0%, 24.0%, and 24.0%, respectively, did so in the placebo group (all P < 0.05). Both the PFS and MFS were significantly improved in patients younger than 50 years and those with free T3 ≥ 4.0 pg/mL by treatment with L-carnitine compared with placebo. Additionally, the MFS was significantly improved in patients taking thyroid hormone after thyroid cancer surgery. These results suggest that L-carnitine supplementation may be useful in alleviating fatigue symptoms in hypothyroid patients, especially in those younger than 50 years and those who have hypothyroidism after thyroidectomy for thyroid cancer (ClinicalTrials.gov: NCT01769157).

Original languageEnglish
Pages (from-to)885-895
Number of pages11
JournalEndocrine Journal
Volume63
Issue number10
DOIs
Publication statusPublished - 2016

Keywords

  • Fatigue
  • Fatigue severity scale
  • Hypothyroidism
  • L-carnitine
  • Wessely and powell score

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology

Fingerprint Dive into the research topics of 'L-carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: A randomized, double-blind, placebo-controlled trial'. Together they form a unique fingerprint.

Cite this