Effect of Growth Hormone Replacement on BMD in Adult‐Onset Growth Hormone Deficiency

To determine if replacement of GH improves BMD in adult‐onset GHD, we administered GH in physiologic amounts to men and women with GHD. GH replacement significantly increased spine BMD in the men by 3.8%. Introduction: Growth hormone (GH) deficiency (GHD) acquired in adulthood results in diminished BMD; the evidence that replacement of GH improves BMD is not conclusive. We therefore performed a randomized, placebo‐controlled trial to determine whether GH replacement would increase lumbar spine BMD in a combined group of men and women with adult‐onset GHD. Materials and Methods: We randomized 67 men and women to receive GH (n = 33) or placebo (n = 34) for 2 yr. The GH dose was initially 2 μg/kg body weight/d, increased gradually to a maximum of 12 μg/kg/d and adjusted to maintain a normal IGF‐I concentration for age and sex. BMD was assessed before treatment and at 6, 12, 18, and 24 mo of treatment. Fifty‐four subjects completed the protocol. Results: BMD of the lumbar spine in the entire group increased by 2.9 ± 3.9% above baseline in the GH‐treated subjects, which was significantly (p = 0.037) greater than the 1.4 ± 4.5% increase in the placebo‐treated subjects. In a secondary analysis, spine BMD in GH‐treated men increased 3.8 ± 4.3% above baseline, which was significantly (p = 0.001) greater than that in placebo‐treated men (0.4 ± 4.7%), but the change in GH‐treated women was not significantly different from that in placebo‐treated women. Treatment with GH did not increase total hip BMD more than placebo treatment after 2 yr. Conclusions: We conclude that GH replacement in men who have adult‐onset GHD improves their spine BMD, but we cannot draw any conclusions about the effect of GH replacement on spine BMD in women with adult‐onset GHD.