Dietary sodium:potassium ratio and CVD risk factors among Japanese adults: a retrospective cross-sectional study of pooled data from the National Health and Nutrition Survey, 2003-2017.

ABSTRACT

Few studies have reported associations between the NaK ratio and risk factors related to CVD among the general population in Asian countries. This study aimed to investigate the dietary NaK ratio association with CVD risk factors among Japanese adults. This retrospective cross-sectional study included 48 800 Japanese participants (19 386 men and 29 414 women) aged ≥20 years, registered in the 2003-2017 National Health and Nutrition Survey. Multivariate OR and 95 % CI for risk of hypertension, high glycated HbA1c levels, hypercholesterolaemia, low serum levels of HDL-cholesterol and high non-HDL-cholesterol levels according to the NaK ratio were estimated using logistic regression models. Dietary NaK ratio decreased for both men and women from 2003 to 2017. Higher NaK ratio and higher hypertension prevalence were observed (multivariate OR (fifth v. first quintiles) 1·27, 95 % CI 1·15, 1·40; Pfor trend < 0·001 for men and 1·12, 95 % CI 1·01, 1·23; Pfor trend = 0·007 for women). Higher NaK ratio was associated with higher prevalence of high HbA1c levels in men (multivariate OR 1·56, 95 % CI 1·24, 1·96). Prevalence of low HDL-cholesterol levels was increased with higher NaK ratio (Pfor trend =0·002 for men and <0·001 for women). No significant associations were found between NaK ratio and hypercholesterolaemia in men or high non-HDL-cholesterol levels in both men and women. Our findings suggest that dietary NaK ratio is associated with several CVD risk factors among Japanese adults.