Ps-bpp06-4: age-dependent increase in dietary salt intake in the japanese adults

Objective: More than half of all cardiovascular disease deaths have been attributed to high blood pressure. Although numerous factors are involved in the development of hypertension, excess dietary salt intake is quite important because it is a modifiable factor. Obviously, tracking alterations in salt intake with age is important for developing population-based strategies to lower salt intake. However, how salt intake changes with age at the individual level has not been intensively studied in the general population. Thus, the present study was designed to investigate changes in salt intake with age in individuals in the general population. Design and Methods: In this observational follow-up study, apparently healthy men and women age > 30 years who participated in a baseline medical checkup (2008–2009) at our center and had a medical checkup 10 years later (n = 2598) were enrolled. Salt intake was estimated by spot urine analysis. Yearly changes in salt intake were also assessed in participants with complete annual data over the course of 10 years from baseline (n = 1543). Results: The follow-up study demonstrated increased salt intake (8.8 ± 2.0 to 9.3 ± 2.1 g/day, P < 0.001) with increasing age (54.0 ± 9.7 to 64.0 ± 9.8 years). Salt intake increased year over year in participants who had a health checkup annually for the 10-year follow-up period (n = 1543; analysis of variance, P < 0.001). The increase in salt intake with age correlated with an increase in blood pressure. Then, regional levels of salt intake in the baseline period (between July 2008 and June 2009) and the period 10 years later (between July 2018 and June 2019) were compared using cross-sectional analyses. The propensity-matched model revealed similar regional levels of salt intake in the baseline period (8.9 ± 2.0 g/day, 55.8 ± 11.1 years, n = 5018) and at 10 years (8.8 ± 2.0 g/day, P = 0.21; 55.9 ± 13.0 years, P = 0.65, n = 5105). Conclusions: Dietary salt intake gradually increased with age in men and women in the general population during the 10-year follow-up period. This should be considered in devising for population-based strategies to lower dietary salt intake.