title: Estimated urinary salt excretion by a self-monitoring device is applicable to education of salt restriction.
abstract: The objective was to investigate the validity of a self-monitoring device that estimates 24-h urinary salt excretion from overnight urine samples as a tool for education regarding salt restriction. Twenty healthy volunteers consumed test meals for 14 days, with salt content as follows: 10 g (days 1-5); 5 g (days 6-8, 12 and 14); and 13 g (days 9-11 and 13). On days 2-15, urinary salt excretion was estimated from overnight urine samples by a self-monitoring device. Twenty-four-hour urine samples were collected on days 5 and 8 to measure salt excretion directly. Blood pressure was measured in the morning and during sleep on days 1-15. Estimated urinary salt excretion measured by the device showed a correlation with salt intake, and the ratio of estimated urinary salt excretion to salt intake was 0.84±0.10 (days 2-6), 1.27±0.28 (days 7-9), 0.70±0.11 (days 10-12), 1.37±0.22 (day 13), 0.68±0.13 (day 14) and 1.33±0.19 (day 15). The correlation between estimated urinary salt excretion measured by a device and directly measured 24-h urinary salt excretion was significant (r=0.65, P<0.05) during the period of 10 g salt intake, but not during 5 g salt intake. Blood pressure in the morning was not influenced by the change in salt intake, but systolic pressure during sleep showed a significant increase or decrease according to the levels of salt intake. In conclusion, a self-monitoring device, which can estimate 24-h urinary salt excretion from overnight urine samples, is considered to be a practical tool for education regarding salt restriction, although a similar future investigation is needed in older and/or hypertensive subjects.
authors.affiliation: Department of Nutritional Sciences, Faculty of Nutritional Sciences, Nakamura Gakuen University, Fukuoka, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Yasutake
authors.affiliation: Department of Health and Nutrition Sciences, Faculty of Health and Nutrition Sciences, Nishikyushu University, Saga, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Horita
authors.affiliation: Health Care Center, Fukuoka University, Fukuoka, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Murata
authors.affiliation: Health Care Center, Fukuoka University, Fukuoka, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Koyama
authors.affiliation: Health Care Center, Fukuoka University, Fukuoka, Japan.
authors.forename: Munechika
authors.initials: M
authors.lastname: Enjoji
authors.affiliation: Hypertension Center, Steel Memorial Yawata Hospital, Kitakyushu, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Tsuchihashi
mesh_terms: D001794:Blood Pressure; D004039:Diet, Sodium-Restricted; D005260:Female; D006801:Humans; D006973:Hypertension / Q000178:diet therapy*; D008297:Male; D008991:Monitoring, Physiologic; D017673:Sodium Chloride, Dietary / Q000652:urine*; D055815:Young Adult
chemical_list: D017673:Sodium Chloride, Dietary