Bone Metabolism During Chronic Growth Hormone Deficiency – Experimental and Clinical Studies

Abstract

Adult-onset growth hormone deficiency (AO-GHD) is most often caused by pituitary or hypothalamic tumours or their treatment, and may serve as a model where the effect of chronic GH deficiency on skeletal metabolism can be studied. While the low bone mass in adults with childhoodonset GHD (CO-GHD) may be explained by deficient bone accretion during childhood, decreased bone mass in AO-GHD may be caused by imbalanced bone remodelling. These patients have secondary osteoporosis characterised by reduced bone mass, decreased bone turnover measured by biochemical markers and increased fracture risk. However, studies on the impact of GH substitution have yielded conflicting results, probably due to high doses and short treatment periods. Longer studies, with treatment periods of one year or more, have shown significant increases in bone mass and turnover.