Urinary excretion of creatinine of children under different nutritional conditions.

I N 190S, Shaffer’ demonstrated that the daily excretion of creatinine in adult man is remarkably constant over long periods of time, even under the most varied circumstances. Because the quantity excreted is little affected by diet, exercise or volume of urine, the daily creatinine excretion is used to determine the completeness of twenty-four hour urine collections. Since creatinine excretion is determined principally by lean body mass,’m the number of milligrams excreted in twenty-four hours per kilogram of body weight, the “creatinine coeficient,” has long been used as an index of the relative amount of muscle in an mdividual. The dlaily creatinine excretion of obese persons is low in relation to their ideal weight.5 When overweight is reduced by dietary nueans, the absolute excretion of creatinine does not change. On the other hand, persons with below normal weights tend to have abnormally low “creatinine coefficien ts” which reflect subnormal development of niuscle mass. Recently, Stearns et al.6 have summarized the results of twenty-five years of investigation in a “creatinine coefficient” curve for well nourished children one to ten years of age in Iowa. Both Talbot7 and Daniels and Hejinian8 have used the “creatinine coefficient” as an index of nutritional status in children although the latter prefer to relate creatinine excretion to height for this purpose.