Urinary cyclic AMP in spot urine of healthy children

Abstract

We present reference values for the excretion of cAMP in spot urine collected between 09.00 and 12.00 hours in 143 healthy children aged 2-200 months. The excretion of cAMP was creatinine-corrected and expressed as a substance concentration ratio (UcAMP/crea)U due to a positive significant correlation between the excretion of cAMP and creatinine (r = 0.68, p less than 0.001). The mean value (95% significance limits) for (UcAMP/crea)U was 748 mumol/mol (254-2206 mumol/mol). A logarithmic transformation of the ratio was used, since preliminary analysis showed uneven distribution; when the logarithmic transformation was used, the data appeared evenly distributed. There was no significant difference between the results for girls and boys. The value of lg(UcAMP/crea)U was related to the age or body surface area with decreasing values at higher age or body surface area. (r = -0.55 and r = -0.57, p less than 0.001). Spot urine for measurement of urinary cAMP instead of a 24 h collection appears preferable due to the practicability of the test in children.