ESPE Yearbook of Paediatric Endocrinology

To read the full abstract: Horm Res Paediatr. 2019;92:293–301

Growth hormone deficiency (GHD) in childhood may influence bone accrual and bone peak mass, ultimately affecting bone density in adulthood (1). In prepubertal GHD children, there is no evidence of increased risk of fractures, but relative lower bone density measured by dual X ray absorptiometry (DXA) has been reported. Interpretation of DXA values in small children is biased by bone size, and furthermore is not an adequate tool to assess bone architecture (2). High resolution peripheral quantitative computed tomography (HR-pQCT) is able to assess trabecular and cortical bone, thus providing an indirect index of bone strength (2)(3).

In this cross-sectional study, 30 prepubertal GHD boys (age 5–11 years) were compared to 15 healthy children with normal height, by DXA and HR-pQCT. GHD boys were younger and shorter than controls (P <0.001). In GHD boys, IGF-I levels correlated with DXA whole body BMD (R =0.73; P =0.003) and lean mass (R =0.76; P =0.002). Peak GH responses to stimulation test correlated negatively with visceral adipose tissue (P = 0.01) and fat mass (P = 0.01). At the radius, GHD boys had smaller HR-pQCT cortical perimeter and trabecular cross-sectional areas than controls. No differences were found in microarchitectural structure and bone strength between the two groups.

The authors concluded that prepubertal GHD boys had deficits in bone geometry, not visible on DXA, independent of age, height z score, lean body mass and vitamin D levels. This is the first study to apply this detailed HR-pQCT bone analysis in prepubertal GHD patients. Larger studies are warranted to confirm these preliminary results showing bone geometry alterations not detectable with DXA in GHD children.

References:

1. Rizzoli R, Bianchi ML, Garabédian M, McKay HA, Moreno LA. Maximizing bone mineral mass gain during growth for the prevention of fractures in the adolescents and the elderly. Bone. 2010 Feb; 46(2):294–305.

2. Bachrach LK, Gordon CM; SECTION ON ENDOCRINOLOGY. Bone Densitometry in Children and Adolescents. Pediatrics. 2016 Oct;138(4):e20162398.

3. Mata-Mbemba D, Rohringer T, Ibrahim A, Adams-Webberc T, Moineddin R, Doria AS, Vali R. HR-pQCT imaging in children, adolescents and young adults: Systematic review and subgroup meta-analysis of normative data. PLoS One. 2019 Dec 13;14(12):e0225663.