Validation of a self-monitoring device for estimating 24-hour urinary salt excretion.
BACKGROUND
The purpose of this study was to investigate the relationship between salt intake and urinary salt excretion and to examine the validity of a self-monitoring device for estimating 24-h urinary salt excretion from overnight urine samples.


METHODS
Twelve young, healthy female volunteers consumed test meals from days 1 to 14 and estimated urinary salt excretion on days 2-15 by using a self-monitoring device. The salt content of the test meals was as follows: 10 g (days 1-5), 6 g (days 6-8), 13 g (days 9-11), 6 g (day 12), 13 g (day 13), and 6 g (day 14).


RESULTS
The average 24-h urinary salt excretion (the ratio of urinary salt excretion to salt intake of the previous day) estimated from the overnight urine samples was as follows: 8.01±1.15 g (0.73±0.11) on days 2-6, 5.86±0.85 g (1.01±0.15) on days 7-9, 9.69±1.64 g (0.74±0.13) on days 10-12, 6.51±1.56 g (1.03±0.25) on day 13, 8.60±3.25 g (0.71±0.14) on day 14, and 6.28±1.31 (1.05±0.22) on day 15. Thus, the salt excretion/salt intake ratio was approximately 0.8 during the high-salt phase and 1.0 during the low-salt phase.


CONCLUSIONS
The estimation of 24-h urinary salt excretion from overnight urine samples by using a self-monitoring device is a reasonably valid method in this young and healthy female population for detecting daily changes in salt intake.
Department of Health and Nutrition Sciences, Faculty of Health and Social Welfare Sciences, Nishikyushu University, Kanzaki, Japan. yasutakekenichiro@gmail.com
Kenichiro
K
Yasutake
Kayoko
K
Sawano
Naoko
N
Shono
Takuya
T
Tsuchihashi
D015415:Biomarkers / Q000652:urine; D001794:Blood Pressure; D002149:Energy Intake; D005260:Female; D006801:Humans; D062407:Meals; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D011446:Prospective Studies; D012648:Self Care / Q000295:instrumentation; D012965:Sodium Chloride / Q000652:urine*; D055815:Young Adult
D015415:Biomarkers; D012965:Sodium Chloride