Effect of growth hormone on bone status in growth hormonedeficient adults

Abstract

Background: Growth hormone deficiency (GHD) is associated with reduced bone mineral content and increased risk of osteoporotic fractures. Reduced peak bone mass might explain the low bone mineral density (BMD) among patients with childhood onset GHD (CO-GHD) whilst the cause of osteopenia in adult-onset GHD (AO-GHD) is not fully understood. Objectives: Prospective multicentric study to asses bone status in GHD adults after two years of recombinant growth hormone replacement treatment. Methods: In 94 GHD adults (49 men; Ø 34.5 yrs) we have measured BMD and bone markers (CTX, osteocalcin) during two years of rhGH treatment (at baseline, after 3 and 6 months, and after 1 and 2 years). Patients were adequately substituted for GHD and other pituitary deficiencies. Results: We have observed an increase in BMD-lumbar spine: n=42, 0.8155→0.9418 g/cm2, p<0.0001; femoral neck n=41; 0.8468→0.9031; p= 0.0004; BMD-whole body 1.0179→1.0774; p=0.0003. We have compared gender difference: BMD-L-spine by 15.8 % in men (n=21) and by 5.6 % in women (n=19) (p= 0.008); BMDfemoral neck increased by 11.03 % in men and by about 3.0 % in women (p=0.032). In women, the initial decrease in BMD was recorded after 3 months. CO-GHD adults yielded a higher increase in BMD -L-spine (16.6 %, p=0.022). A correlation exists between IGF-I levels and BMD in lumbar spine (1st year: R=0.348, p=0.026; 2nd year: R= 0.33, p=0.0081) and between IGF-I and osteocalcin (1st year: R=0.383; p=0.0038). Conclusion: Two-year therapy with recombinant human growth hormone improved bone status. IGF-I appears to be a good indicator of rhGH effect on bone.