Development and preliminary validation of a prediction formula of sodium and sodium-to-potassium ratio based on multiple regression using 24-h urines

• Published in: Scientific reports 2024-04, Vol.14 (1), p.9704-9704, Article 9704
• Main Authors: Yamagishi, Marina, Takachi, Ribeka, Ishihara, Junko, Maruya, Sachiko, Ishii, Yuri, Kito, Kumiko, Nakamura, Kazutoshi, Tanaka, Junta, Yamaji, Taiki, Iso, Hiroyasu, Iwasaki, Motoki, Tsugane, Shoichiro, Sawada, Norie
• Format: Article
• Language: English
• Subjects: 24-h urine; 692/53/2423; 692/700/2814; 692/700/478/174; Adult; Aged; Aged, 80 and over; Correlation coefficient; Eating behavior; Epidemiology; Excretion; Feeding Behavior; Female; Food composition; Humanities and Social Sciences; Humans; Male; Middle Aged; multidisciplinary; Potassium; Potassium - urine; Prediction formula; Predictions; Regression analysis; Science; Science (multidisciplinary); Sodium; Sodium - urine; Sodium, Dietary - analysis; Sodium, Dietary - urine; Sodium-to-potassium ratio; Soy sauce; Surveys and Questionnaires
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-60349-3

Accurate measurement of sodium intake in the diet is challenging, and epidemiological studies can be hampered by the attenuation of associations due to measurement error in sodium intake. A prediction formula for habitual 24-h urine sodium excretion and sodium-to-potassium ratio might lead to more reliable conclusions. Five 24-h urinary samples and two Food Frequency Questionnaires (FFQs) were conducted among 244 Japanese participants aged 35–80 years. We conducted multivariate linear regression analysis with urinary excretion as dependent variables and eating behaviour and food frequency as independent variables. Empirical weights of sodium excretion and sodium-to-potassium ratio were extracted. Preliminary validity was also assessed by randomly dividing the subjects into development and validation groups based on the correlation coefficient between estimates by the prediction formula and urinary excretion. Taste preference, soy sauce use at the table, frequency of pickled vegetables intake and number of bowls of miso soup were extracted as determinants of sodium excretion. Correlation coefficients between the estimates and urinary excretion for men and women were 0.42 and 0.43, respectively, for sodium and 0.49 and 0.50, respectively, for sodium-to-potassium ratio. This prediction formula may provide more accurate estimation of sodium intake and sodium-to-potassium ratio than the food composition approach.