Association between parent-reported salt-related behaviors and estimated urinary salt excretion: a cross-sectional study of health checkups in 4-year-old children

Although salt-related behaviors may influence urinary salt excretion in early childhood, this relationship remains unclear. This study aimed to examine salt-related behaviors using data from a salt check sheet and urinary salt excretion parameters using spot urine samples from 4-year-old children. This cross-sectional study included all 4-year-old children who underwent health checkups in Ohnan Town, Shimane Prefecture. The study sample consisted of 109 children (49 boys). Measures from spot urine samples included estimated salt excretion (g/day) and the sodium-potassium (Na/K) ratio. Salt-related behaviors were assessed using a salt check sheet that was completed by the parents or guardians. The associations between salt-related behaviors and urinary salt excretion parameters were analyzed using a generalized linear model. The median (M) and interquartile range (IQR) for urinary measures in 4-year-old children were as follows: estimated salt excretion (M = 4.4, IQR: 3.3-6.2) and Na/K ratio (M = 2.3, IQR: 1.4-3.3). The low frequency of consumption of high-salt foods ("such as pickles, pickled plums, etc." and "noodles such as udon and ramen") was associated with low salt excretion and low Na/K ratio. However, in the case of "consumption of udon, ramen, or other soups", the Na/K ratio was higher for "About half a bowl" and "Some" than for "An entire bowl." Additionally, for "eating out or having convenience-store-bought bento (lunch plate) for lunch", the Na/K ratio was higher for "No" than for "Almost every day." In conclusion, the frequency of high-sodium food intake was associated with both urinary sodium excretion and the Na/K ratio in 4-year-old children. Longitudinal investigations using the 24-hour urine collection method are needed to confirm these salt-related behaviors.