SUMMARY This study explored the association between sodium excretion and blood pressure (BP). A new method was used to minimize the measurement error introduced by the large intrinsic variability of 24-hour sodium excretion. The ratio of intra-to interindividual variation was used to estimate the number of measurements needed to characterize the individual. When seven consecutive 24-hour samples were collected from 73 children, ages 11-14 years, a significant correlation between mean individual sodium excretion and BP was demonstrated. The independent relationship persisted when controlling for height, weight, pulse, age, sex and race (p = 0.045), but was eliminated by simultaneously considering mean creatinine excretion. Although the cross-sectional association described is quantitatively weak, a linear relationship between BP and sodium over the range consumed in this society could be important for prevention.CHRONIC HIGH SODIUM INTAKE has long been thought to play a role in the development of high blood pressure.' Cross-cultural comparisons support the hypothesis of a sodium-blood pressure relationship, and extremes of sodium intake, both high and low, have been shown to alter blood pressure.1-2 The association within a population, however, over the range usually ingested by industrialized societies, has been difficult to demonstrate."1-8 Using a new approach, this study shows a positive cross-sectional association between sodium excretion and blood pressure in children ages 11-14 years.'9' 20 MethodsThe study was an extension of a blood pressure survey among children in the parochial schools of Chicago (Levinson S, Berkson D: manuscript in preparation). Through contact with interested science teachers and school personnel, two schools were chosen for an intensive study of the relation of sodium excretion and blood pressure. The proposed study was presented as part of the curriculum to science classes of the sixth through eighth grades and the children were asked, with parental consent, to volunteer. Previous experience and statistical analysis indicated that the crucial methodologic problem involved minimizing sizable measurement error introduced by a high ratio of intra-to interindividual variation in daily sodium excretion.19 Based on findings in adults, we estimated that seven 24-hour urinary sodium determinations were needed to characterize the individual.19Groups of six to 10 children were carefully instructed on the procedure for collection of 24-hour urine samples. The sample was divided into an overnight portion, defined as any urine voided after going to bed at night and first morning void, and daytime sample, the remainder of the day. Carrying cases and plastic bottles were provided each student on a daily basis. Every effort was made to collect the seven samples on consecutive days. When a child was ill, missed school or accidently discarded urine, an additional 24-hour sample was obtained the following week. Although not necessarily the same day of the week, repeat weekday samples were collected ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.