Bone mineral density, bone metabolism and body composition of children with chronic renal failure, with and without growth hormone treatment

OBJECTIVE Osteopenia has been reported in adult patients with chronic renal failure (CRF), only a few studies have been performed in children. The obj ective of this study was to evaluate bone mineral density (BMD), bone turno ver, body composition in children with CRF and to study the effect of GH on these variables. DESIGN Two groups were identified: patients with growth retardation who rec eived GH (GH-group) and patients most of whom were not growth retarded who did not receive GH (no-GH-group). After an observation period of 6 months, the patients in the GH-group started GH treatment. Patients were studied ev ery 6 months during 18 months. PATIENTS Thirty-six prepubertal patients (27 boys and 9 girls), mean age 7. 9 years, with CRF participated in the study. The GH-group consisted of 17 p atients of whom 14 completed one year treatment. The no-GH-group consisted of 19 patients, of whom 16 were followed for 6 months, 14 for 12 months and 13 for 18 months. MEASUREMENTS Lumbar spine BMD, total body BMD and body composition were ass essed by dual energy X-ray absorptiometry, compared to age-and sex-matched reference values of the same population and expressed as standard deviation scores (SDS), BMD of appendicular bone was measured by quantitative microd ensitometry (QMD). Blood samples were obtained to assess bone metabolism an d growth factors. RESULTS Baseline mean lumbar spine and total body BMD SDS of ail patients w ere not significantly different from normal. Mean lumbar spine and total bo dy BMD SDS did not change significantly in the GH-group during GH treatment . The change of QMD at the midshaft during the first 6 months of GH treatme nt was significantly smaller than during the observation period (P< 0.01). Height SDS and biochemical markers of both bone formation and bone resorpti on increased significantly during GH treatment; 1,25-dihydroxyvitamin D rem ained stable. Lean tissue mass increased (P<0.001) and percentage body fat decreased (P< 0.01) during GH treatment. BMD, the biochemical markers of bo ne turnover which are independent of renal function, and body composition r emained stable in the no-GH-group. CONCLUSIONS Mean lumbar spine and total body BMD of children with chronic r enal failure did not differ from healthy controls. The lack of a GH-induced increase in 1,25-dihydroxyvitamin D levels, probably due to treatment with alpha-calcidol, might be linked to the absence of a response in BMD during GH treatment in children with chronic renal failure.