The IGF/IGFBP system in relation to macroscopic bone architecture in pediatric renal transplant patients

• Published in: Pediatric nephrology (Berlin, West) West), 2010-04, Vol.25 (4), p.659-667
• Main Authors: Kiepe, Daniela, Rüth, Eva-Maria, Blum, Werner F., Mohan, Subburaman, Weber, Lutz T., Tönshoff, Burkhard
• Format: Article
• Language: English
• Subjects: Adolescent; Analysis; Bone and Bones - diagnostic imaging; Bone diseases; Child; Chronic Kidney Disease-Mineral and Bone Disorder - etiology; Chronic Kidney Disease-Mineral and Bone Disorder - metabolism; Chronic Kidney Disease-Mineral and Bone Disorder - pathology; Cross-Sectional Studies; Female; Fractures; Glomerular Filtration Rate; Humans; Insulin-Like Growth Factor Binding Proteins - blood; Insulin-like growth factors; Kidney Failure, Chronic - surgery; Kidney Transplantation; Kidney transplants; Kidneys; Male; Medicine; Medicine & Public Health; Metabolism; Muscle, Skeletal - diagnostic imaging; Muscle, Skeletal - pathology; Necrosis; Nephrology; Organ transplant recipients; Original Article; Patients; Pediatrics; Prospective Studies; Protein binding; Radioimmunoassay; Somatomedins - analysis; Somatomedins - deficiency; Tomography; Tomography, X-Ray Computed; Transplantation; Urology; Young Adult
• ISSN: 0931-041X; 1432-198X
• DOI: 10.1007/s00467-009-1405-5

The post-transplant bone disease of the peripheral skeleton in pediatric renal transplant recipients is characterized by an inadequately thin bone cortex in relation to muscular force. A major hormonal modulator of periosteal growth is the insulin-like growth factor (IGF)/IGF binding protein (IGFBP) system. We therefore hypothesized that the reduced cortical thickness in these patients may be due to functional IGF deficiency. To test this hypothesis, we investigated 55 patients (mean estimated glomerular filtration rate 86.3 ± 30.0 ml/min/1.73 m 2 ) in a cross-sectional study. Parameters of macroscopic bone architecture and forearm muscle size were analyzed by peripheral quantitative computed tomography (pQCT), and serum IGF/IGFBP system components were measured by specific radioimmunoassays. The mean (± standard deviation) standardized serum IGF-I (0.20 ± 1.16 score) level was normal, while the mean IGF-II (1.16 ± 0.11 score) level was significantly elevated. Serum IGFBP-1 and IGFBP-2 levels were not altered, whereas the IGFBP-3 (1.34 ± 0.15 score) level was significantly increased. The serum IGFBP-4 level was slightly elevated (by 11%), the IGFBP-6 level was markedly (2.3-fold) elevated, while the IGFBP-5 level was comparable to that of the control. The respective age-adjusted cortical thickness at both the proximal ( r  = 0.407, P