[Local reference intervals for the excretion of creatinine in urine for an adult population]

To present the height- and sex-specific reference intervals for the urinary excretion of creatinine in cuban subjects with ages between 19-58 years.

The standards advanced by Bistrian (1985) for anglosaxon subjects have been traditionally used for the construction of the Index of Creatinine Excretion (ICE). This practice could lead to diagnostic errors in the case of ICE calculation for non-anglosaxon populations differing in dietetic behaviour and body composition.

Values of urinary excretion of Creatinine measured in 103 men and 112 women with ages between 19 and 58 years, and preserved nutritional wellbeing (weight within the interquartile range for height; 18.5 < or = body mass index < or = 30.0 kg/m2) and renal function (serum Creatinine < or = 132 mumol/l) were drawn retrospectively from the databases of the Section of Urinalysis, Service of Clinical Laboratory, "Hermanos Ameijeiras" Hospital (La Habana, Cuba). For each sex, the regression line urinary-Excrecion-of-Creatinine = c + d. height, where c, d: parameters dependent on the subject's height, were constructed. The predicted values of the urinary excretion of Creatinine for the cuban subjects were derived from the 100 (1-alpha)% prediction intervals (PI) of the regression line.

The urinary excretion of Creatinine for a 170 cm-height, 66.5 kg-weight, cuban male with age between 19-58 years, was 1216.19 mg/24 hours (95% Pl: 821.02-1611.36 mg/24 hours). The urinary excretion of Creatinine for a 160 cm-height, 59.7k Kg-weight, cuban female with age between 19-58 years, was 852.00 mg/24 hours (95% Pl: 420.15-1283.84 mg/24 hours). After taking into account the subject's weight, the urinary excretion of Creatinine for the cuban subjects was lower than that of their anglosaxon counterparts. There was not correlation between the age of the subject and the urinary excretion of Creatinine.

We recommend the use of the values of the urinary excretion of Creatinine tabulated in this article in the conduction of studies of body composition and nutritional assessment.