Spot urine osmolality/creatinine ratio in healthy humans.

Background: Spot urine albumin/creatinine ratio is a reliable estimate of 24-hour urine albumin excretion. In a pilot study, we observed that the spot urine osmolality/creatinine ratio (U(osm)/U(cr)) in healthy adults is reproducible. Therefore, we postulated that U(osm)/U(cr) of a spot urine sample may give an overall estimate of urinary excretion of solutes, renal concentrating ability and body hydration status.