Neuromuscular dysfunction in adult growth hormone deficiency

Clin Endocrinol (Oxf). 2003 Oct;59(4):450-8. doi: 10.1046/j.1365-2265.2003.01866.x.


Background: Adult growth hormone deficiency (AGHD) is associated with fatigue, tiredness and myalgias, which improve after initiating recombinant human GH (rhGH) therapy.

Aim: To conduct an extensive neuromuscular investigation of patients with AGHD in an attempt to explain their neuromuscular symptoms.

Patients and methods: Twenty adult patients (11 males) with untreated GHD of whom 10 were childhood-onset (CO) underwent a prospective neurological protocol, including physical examination and a neurophysiological study that comprised sensory and motor neurography, repetitive stimulation, electromyogram (EMG) and interference pattern analysis (IPA). In the first seven patients (four CO), a biceps muscle biopsy was also performed for histochemical analysis and Western blot, and investigation of signal transducers and activators of transcription (STATs)-1 and -3 and the two isoforms STAT-5a and -5b.

Results: Neuromuscular examination, sensory and motor neurography and repetitive stimulation were normal in 20/20 patients. Fourteen [seven CO and seven adult-onset (AO)] of the 20 patients had abnormal EMG and/or IPA suggestive of a neurogenic involvement. In those seven patients with initially abnormal results, who also remained on regular rhGH for at least 1 year, repeated IPA was normal in six and improved in the remaining patient (P=0.004). The biceps muscle biopsy disclosed abnormal groupings in the seven cases tested, indicative of a neurogenic pattern. No changes in skeletal muscle STAT-1 and -3 were seen compared to controls, but a marked increase in both STAT-5 isoforms was observed in all seven patients.

Conclusion: Skeletal muscle of patients with both adult-onset and childhood-onset adult GH deficiency shows a neuromuscular dysfunction, indicated by the muscle biopsy and the neurophysiological study, which in the subgroup of treated patients responds positively to rhGH therapy. The results obtained suggest that the STAT-5 signal transduction pathway in muscle is abnormal in adult GH deficiency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Blotting, Western
  • DNA-Binding Proteins / analysis
  • Electromyography
  • Female
  • Human Growth Hormone / deficiency*
  • Human Growth Hormone / therapeutic use
  • Humans
  • Male
  • Middle Aged
  • Milk Proteins*
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology
  • Neural Conduction / physiology
  • Neurologic Examination
  • Neuromuscular Diseases / metabolism
  • Neuromuscular Diseases / pathology
  • Neuromuscular Diseases / physiopathology*
  • Prospective Studies
  • STAT5 Transcription Factor
  • Signal Transduction / physiology
  • Trans-Activators / analysis


  • DNA-Binding Proteins
  • Milk Proteins
  • STAT5 Transcription Factor
  • Trans-Activators
  • Human Growth Hormone