Renal net acid excretion related to body surface area in children and adolescents

Renal net acid excretion (NAE) was determined in 2307 24-h urine samples from 566 healthy children and adolescents (285 boys, 281 girls; 2.7–18.3 years) participating in the DONALD (Dortmund Nutritional and Anthropometric Longitudinally Designed) Study. NAE is presented for 32 different age and sex groups. Before puberty there is an age-dependent increase in absolute values of NAE (mmol/day) and an age-dependent decrease in NAE related to body weight (mmol/kg per day). NAE related to body surface area (mmol/day per 1.73 m²) was independent of age with higher values in boys than in girls. In summary, body surface area is an appropriate adjustment parameter for renal NAE in the age-independent assessment of the renal acid load in German children and adolescents. Received: 12 November 1999 / Revised: 15 March 2000 / Accepted: 17 April 2000