Effects of L-carnitine on Hypothyroidism
Effects of L-carnitine on Hypothyroidism
L-carnitine and thyroid hormone tended to antagonize reciprocally in human body. Urinary
 excretion of L-carnitine decreased in hypothyroid patients, and levothyroxine supplementation
 increased excretion of L-carnitine. The investigators hypothesized that supplying L-carnitine
 to hypothyroid patients with fatigue symptom could improve the quality of life, and fatigue
 score in them. Therefore, the investigators planned to compare the efficacy of L-carnitine
 and placebo in hypothyroid patients who had taken levothyroxine.
Inclusion Criteria:

 -  Clinical diagnosis of hypothyroidism with fatigue symptom

 -  Currently use of the same amount of levothyroxine over at least six months

 -  Normal serum free T4 level

 Exclusion Criteria:

 -  Current smoker

 -  Serum hemoglobin level of under 12mg/dL

 -  Clinical diagnosis of diabetes mellitus or fasting serum glucose level ≥ 126mg/dL or
 HbA1c level ≥ 6.5%

 -  History of significant heart failure

 -  History of large amount of alcohol consumption

 -  Uncontrolled hypertension (systolic blood pressure ≥ 160 millimeter of mercury (mmHg)
 or diastolic blood pressure ≥ 100 mmHg

 -  pregnant, or planning to be pregnant, or breast feeding women

 -  aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥ 2 times of normal
 limit

 -  serum Cr level > 2.0mg/dL