Objective: To understand the situation and problems on water drinking and table salt intake in school children in Shandong Province, to discuss preliminarily the effects of water drinking on the excretion of sodium.
Methods: School children aged 8-10 years in Dezhou city, Shandong Province were chose as the subjects, 3- day dietary survey method was adopted to survey the children's situation on table salt intake and daily water drinking, 24-hour urine was sampled for the determination of urinary sodium concentration and calculation of daily sodium excretion, the effects of water drinking on the excretion of sodium and the status of salt intake in children were evaluated.
Results: A total of 554 school children in total were surveyed, included 246 boys and 298 girls. The results shown that there were about 80. 7%( 447 /554) school children had inadequate daily drinking water intake, and 28. 7%( 159 /554) children had excessiveintake of salt. The water drinking was increased significantly when the salt intake exceeded requirement. However, the excretion of sodium didn't increase obviously. The data also shown that a great part of the subjects drunk less water than recommendation. The urine volume didn't decrease along with the decrease of drinking water while water drinking was not enough. We observed that the urinary sodium concentration climbed up apparently when those drunk water less than 600 m L per day( P < 0. 05). The results of correlation analysis indicated that a strong positive relationship existed between urinary sodium concentration and urinary sodium excretion( r = 0. 635, P = 0. 000), and a weak negative correlation between water drinking and urinary sodium concentration( r =- 0. 272, P = 0. 000).
Conclusion: Inadequate water drinking is a serious problem in the school children. Appropriately increase water drinking while limited the salt intake is benefit for the maintainance of water-electrolyte metabolism.
Keywords: 24-hour urine; children; drinking water; sodium.