Current address: Renal Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, England.
Electrolyte Excretion in 12-hour Urine and in Spot Urine
Relationship to Plasma Renin Activity and Aldosterone Concentration in Older Children
Version of Record online: 21 JAN 2008
Volume 74, Issue 3, pages 394–399, May 1985
How to Cite
UCHIYAMA, M., OTSUKA, T., SHIBUYA, Y. and SAKAI, K. (1985), Electrolyte Excretion in 12-hour Urine and in Spot Urine. Acta Paediatrica, 74: 394–399. doi: 10.1111/j.1651-2227.1985.tb10991.x
- Issue online: 21 JAN 2008
- Version of Record online: 21 JAN 2008
- Submitted July 18, 1984. Accepted Nov. 6, 1984
- Timed urine;
- spot urine;
- sodium excretion;
- plasma renin activity;
- plasma aldosterone concentration
ABSTRACT. Plasma renin activity (PRA) and urinary electrolyte excretion were measured in 137 healthy children aged 6 to 14 years. Plasma aldosterone concentration (PAC) was measured in 52 of the children. Nocturnal 12-hour urine was collected in 110 of the children. Spot urine was collected on two occasions, once just before lying down, once after 90-min supine rest in another 27. Na/K ratio and fractional Na excretion rate (FENa) in 12-hour urine showed a significant inverse correlation with PRA or PAC. Na excretion (mmol/min, mmol/mmol creatinine), Na/K ratio and FENa in the spot urine following 90 min in a supine position showed a significant inverse correlation with PRA or PAC, but they failed to show a significant relationship to PRA or PAC in the spot urine preceding supine rest. A spot urine after 90 min in the supine position is collected easily and hence most appropriate to study the relationship between Na excretion and PRA or PAC clinically.