ICHIHARA Atsuhiro    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position   Professor and Division head
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	Urinary Sodium-to-Potassium Ratio Tracks the Changes in Salt Intake during an Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers.
Journal	Formal name：Nutrients Abbreviation：Nutrients ISSN code：2072664320726643
Volume, Issue, Page	9(9),pp.10.3390/nu9090951
Author and coauthor	YATABE Midori†, IWAHORI Toshiyuki, WATANABE Ami, TAKANO Kozue, SANADA Hironobu, WATANABE Tsuyoshi, ICHIHARA Atsuhiro, Felder Robin A, MIURA Katsuyuki, UESHIMA Hirotsugu, KIMURA Junko, YATABE Junichi*
Publication date	2017/08
Summary	The Na/K ratio is considered to be a useful index, the monitoring of which allows an effective Na reduction and K increase, because practical methods (self-monitoring devices and reliable individual estimates from spot urine) are available for assessing these levels in individuals. An intervention trial for lowering the Na/K ratio has demonstrated that a reduction of the Na/K ratio mainly involved Na reduction, with only a small change in K. The present study aimed to clarify the relationship between dietary Na intake and the urinary Na/K molar ratio, using standardized low- and high-salt diets, with an equal dietary K intake, to determine the corresponding Na/K ratio. Fourteen healthy young adult volunteers ingested low-salt (3 g salt per day) and high-salt (20 g salt per day) meals for seven days each. Using a portable urinary Na/K meter, participants measured their spot urine at each voiding, and 24-h urine was collected on the last day of each diet period. On the last day of the unrestricted, low-salt, and high-salt diet periods, the group averages of the 24-h urine Na/K ratio were 4.2, 1.0, and 6.9, while the group averages of the daily mean spot urine Na/K ratio were 4.2, 1.1, and 6.6, respectively. The urinary Na/K ratio tracked changes in dietary salt intake, and reached a plateau approximately three days after each change in diet. Frequent monitoring of the spot urine Na/K ratio may help individuals adhere to an appropriate dietary Na intake.
DOI	10.3390/nu9090951
PMID	28850062