Local administration of growth hormone stimulates tendon collagen synthesis in elderly men

Research output: Contribution to journalArticlepeer-review


  • Poul Erik Vestergaard
  • Jens Otto Lunde Jørgensen
  • Jens Olesen
  • Ermina Bosnjak
  • Jan Frystyk
  • Henning Langberg
  • Michael Kjaer
  • Mette Damborg Hansen

Colleges, School and Institutes


Tendon collagen content and circulating growth hormone (GH) are reduced in elderly. In a placebo-controlled, double-blinded study, we examined if local injections of rhGH enhance collagen synthesis in healthy elderly men (61 ± 1 yr). Two injections of rhGH or saline (control) were injected into each of the patient's patellar tendons, respectively. Subsequently, tendon collagen fractional synthesis rate (FSR) and an indirect marker of type I collagen synthesis (PINP) were measured. Within the first 6 h after the last injections, a tendency towards a higher tendon collagen FSR was observed in 10 out of 12 subjects (P = 0.08). Similarly, PINP was higher 3-4 h after the last GH injection (P = 0.05). Serum IGF-I did not change from baseline, whereas peritendinous bioactive IGF-I was higher in the GH leg vs. control (P = 0.05). In conclusion, local injections of rhGH increase tendon collagen synthesis in humans, either directly or indirectly by increasing local bioactive IGF-I.


Original languageEnglish
Pages (from-to)1432-1438
Number of pages7
JournalJournal of Applied Physiology
Issue number9
Publication statusPublished - Nov 2012