BACKGROUND: Estimates of daily sodium (Na) and potassium (K) excretion were explicitly biased when using equations for adults. We aimed to develop equations to estimate them using overnight urine from Japanese children and adolescents. METHODS: The subjects comprised 70 students aged 10.49-15.76 years: validation group, n = 34; and verification group, n = 36. Each subject performed two operations of overnight spot urine (U RESULTS: In validation, we formulated Na excretion (mg d CONCLUSION We obtained validated equations to estimate daily Na and K excretion with accessible variables such as Na, K, and Cr concentrations of overnight urine, body height and weight, and age for children and adolescents. When using the obtained equations, caution should be paid to small but definite biases and measurement errors.
Adolescent ; Child ; Creatinine/urine* ; Female ; Humans ; Japan ; Male ; Potassium/urine* ; Sodium/urine*