Serum osteocalcin concentrations in children with chronic renal insufficiency who are not undergoing dialysis. Growth Failure in Children with Renal Diseases Study

Abstract

This report describes the serum osteocalcin values in children with mild to moderate, but relatively stable, renal dysfunction followed in the Growth Failure in Children With Renal Diseases Study. This report is derived from data obtained during the control period (6 months) before the initiation of vitamin D therapy. Up to three measurements per patient were obtained. Serum osteocalcin concentration was compared with creatinine clearance (glomerular filtration rate) calculated by the Schwartz formula; with serum concentrations of alkaline phosphatase, parathyroid hormone, and bicarbonate; and with the percentages of the recommended dietary allowances of calories and protein ingested. By standard correlation techniques, there appeared to be an inverse correlation between calculated creatinine clearance and serum osteocalcin concentration, and a direct correlation between serum osteocalcin and parathyroid hormone values. However, when we employed a statistical technique that takes into account repeated measures in the same patient, no correlation was found between calculated glomerular filtration rate and serum osteocalcin concentration, and no direct correlation was found between serum osteocalcin and parathyroid hormone values. The lack of a correlation between calculated glomerular filtration rate and serum osteocalcin values may be due to large fluctuations in the serum osteocalcin concentration, even though renal function is relatively stable.