Reference interval for serum creatinine in children and adolescents with myelomeningocele

In children and adolescents with myelomeningocele (MMC), the relation between muscle mass and body composition varies considerably, making it difficult to evaluate the relevance of renal function assessments done with serum (s)-creatinine. Therefore, a reference interval for enzymic s-creatinine in individuals with MMC was constructed.

Patients with MMC aged 1.5-18 years who consistently had chromium-51-labelled edetic acid clearance within normal limits (88-132 ml/min/1.73 m(2)) were selected for the study. Included were 52 girls and 71 boys with a total of 471 s-creatinine determinations. Children with normal body composition were used as controls.

The mean s-creatinine concentration at the age of 1.5 years was 22 micromol/l in girls and 21 micromol/l in boys and increased to 38 micromol/l in girls and 58 micromol/l in boys at the age of 18 years. There was no difference between the genders until the age of 12. From the age of 3 years, there was a significantly lower median s-creatinine concentration in the MMC children compared with a healthy age-matched population. The median concentration of the MMC children was equivalent to the 2.5 percentile of the control group.

From the age of 3 years, the reference interval for children and adolescents with MMC showed a lower median concentration for enzymic s-creatinine and a greater interindividual variation compared with the healthy age-matched population.