Bone density and body composition in children with growth hormone insensitivity syndrome receiving recombinant IGF-I.
OBJECTIVE
There are few reports of the metabolic action of insulin-like growth factor 1 (IGF-I) in vivo. Growth hormone insensitivity syndrome is a good model to examine the effects of IGF-I deficiency. This study was designed to assess body composition and bone density in children with growth hormone insensitivity syndrome before and after receiving treatment with recombinant IGF-I.


METHODS
A prospective longitudinal study.


METHODS
Four prepubertal boys age 6.1-9.8 years with short stature due to growth hormone insensitivity syndrome.


METHODS
Assessment of body fat by skinfold thickness measurements and dual energy X-ray absorptiometry (DXA) was made during the first 6 months of recombinant IGF-I treatment. Assessment of lumbar spine bone density by DXA was performed prior to IGF-I treatment and during the subsequent five years.


RESULTS
Each child showed a significant reduction in fat mass (0.26-1.22 kg) after 6 weeks of IGF-I treatment. Bone density prior to treatment was reduced in comparison to age-matched controls but calculated volumetric bone density was within the normal range. Volumetric bone density progressively improved over the 5-year treatment period.


CONCLUSIONS
Children with growth hormone insensitivity syndrome exhibit a metabolic response to IGF-I within 6 weeks analogous to that seen in GH-deficient children receiving GH. Bone density when corrected for body size is within normal limits and demonstrates a response to IGF-I, confirming the anabolic action on bone.
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000187:drug effects; D001823:Body Composition / Q000187:drug effects*; D001827:Body Height / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects*; D002648:Child; D006130:Growth Disorders / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000172:deficiency* / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000627:therapeutic use; D012885:Skinfold Thickness; D013577:Syndrome
D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I