Effect of long-term growth hormone treatment on bone mass and bone metabolism in growth hormone-deficient men.
Long-term GH treatment in GH-deficient men resulted in a continuous increase in bone turnover as shown by histomorphometry. BMD continuously increased in all regions of interest, but more in the regions with predominantly cortical bone.


BACKGROUND
Adults with growth hormone (GH) deficiency have reduced rates of bone turnover and subnormal BMD. GH treatment is effective in enhancing bone turnover as shown by biochemical markers and bone histomorphometric studies. However, it is uncertain whether long-term treatment will result in higher bone mass. In this study, we present BMD and histomorphometric data on 5 years of GH treatment in GH-deficient men.


METHODS
Thirty-eight adult men with childhood onset GH deficiency (20-35 years) were included in the study. Twenty-six of these had multiple pituitary hormone deficiencies and were on stable conventional hormone replacement. BMC (total body) and BMD (lumbar spine and hip) were measured before and after 1, 2, 3, 4, and 5 years of treatment. BMD in various regions of the total body was calculated by computer software (head, trunk, arms, and legs). Transiliac bone biopsies were obtained before and after 1 and 5 years of GH treatment.


RESULTS
Total body BMC increased 18% after 5 years of treatment. This increase was observed in all regions of interest: head, 13.7%; trunk, 27.8%; arms, 24.4%; legs, 13.8%. BMD also increased in all separately measured regions: lumbar spine, 9%; femoral neck, 11%; femoral trochanter, 16%. Lumbar spine area significantly increased (p=0.0002). Histomorphometric data showed increased osteoid surface (p<0.02), osteoid volume (p<0.01), and activation frequency (p<0.006), but trabecular bone volume did not increase significantly. Qualitative assessment of the cortical bone showed endosteal and periosteal bone formation.


CONCLUSIONS
In conclusion, GH considerably increases BMC after long-term treatment. The combination of BMD and histomorphometric data suggests that GH has a greater effect on cortical than on trabecular bone.
Bravenboer
Nathalie
N
Department of Endocrinology, VU University Medical Center, Amsterdam, The Netherlands. n.bravenboer@vumc.nl
Holzmann
Paulien J
PJ
ter Maaten
Jan C
JC
Stuurman
Lotte M
LM
Roos
Jan C
JC
Lips
Paul
P
D000328:Adult; D015519:Bone Density / Q000187:drug effects*; D020249:Hormone Replacement Therapy; D019382:Human Growth Hormone / Q000172:deficiency* / Q000627:therapeutic use*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010012:Osteogenesis / Q000187:drug effects*; D013997:Time Factors
D019382:Human Growth Hormone