Associations between Milk and Dairy Product Intake, Urinary Sodium-to-Potassium Ratio, and Socioeconomic Status in Japanese Male Adolescents

Abstract

Although socioeconomic status (SES) may affect children’s urinary electrolytic excretion and dietary intakes, few studies have reported the association between SES and urinary sodium (Na)-to-potassium (K) ratio in Japanese adolescents and children. Therefore, this study aimed to investigate the association between SES and urinary Na/K ratio (Analysis 1) and between dietary intake and urinary Na/K ratio to determine the SES effects in children and adolescents (Analysis 2). This cross-sectional study included 168 Japanese male adolescent and child football players. The urinary Na/K ratio was calculated from three spot urinary electrolyte values. Multiple regression analysis was performed in both first and second analyses to assess the associations between SES and the urinary Na/K ratio and between dietary intake and the urinary Na/K ratio for ages 9–12 and 13–15 years separately. The mean urinary Na/K ratio was 4.8, with higher SES associated with a lower urinary Na/K ratio. Our results suggested that urinary Na/K ratios in Japanese child football players were high due to poor childhood diets, and higher SES was associated with lower urinary Na/K ratios. Further, milk and dairy products are associated with the urinary Na/K ratio, independent of SES in children and adolescents.

Keywords

• cardiovascular diseases
• adolescents and children
• urinary sodium-to-potassium ratio
• dietary intake
• socioeconomic status