Muscle force and endurance in untreated and human growth hormone or insulin-like growth factor-I-treated patients with growth hormone deficiency or Laron syndrome.

Abstract

Muscle force and endurance of four muscle groups (biceps, triceps, hamstrings and quadriceps) were measured by a computerized device in three groups: (A) 4 boys with isolated growth hormone deficiencies (IGHD) examined before at 10 and 24 months of hGH treatment; (B) 5 children (2 F, 3 M) with Laron syndrome were examined 3.5-4 years after initiation of insulin-like growth factor-I (IGF-I) treatment, and (C) comprised 8 untreated adults (5 F, 3 M) with Laron syndrome. For each patient, 2 matched controls, by age, sex, physical activity and height below the 50th percentile, were examined. GH- or IGF-I-deficient patients before treatment revealed reduced muscle force and endurance. GH treatment (0.6 U/kg/week) restored muscle force and endurance, progressively, mainly in the boys with puberty. Three to 4 years of IGF-I treatment (150 micrograms/kg/day) in patients with Laron syndrome proved to have a weaker effect than GH in restoring muscle force. The difference in effectiveness between hGH and IGF-I in restoring muscle force may be due to either the more marked muscle underdevelopment in Laron syndrome patients than in patients with IGHD or a difference in action potential between the two hormones.

• Authors: O Brat, I Ziv, B Klinger, M Avraham, Z Laron
• Journal: Hormone research (Horm Res) Vol. 47 Issue 2 Pg. 45-8 ( 1997) ISSN: 0301-0163 [Print] Switzerland
• PMID: 9030966 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Human Growth Hormone
• Insulin-Like Growth Factor I

Topics

• Adolescent
• Adult
• Child
• Child, Preschool
• Cohort Studies
• Extremities (physiopathology)
• Female
• Follow-Up Studies
• Growth Disorders (drug therapy, physiopathology)
• Human Growth Hormone (administration & dosage, deficiency, therapeutic use)
• Humans
• Insulin-Like Growth Factor I (administration & dosage, deficiency, therapeutic use)
• Male
• Middle Aged
• Muscle Contraction (drug effects, physiology)
• Physical Endurance (drug effects, physiology)