Objective: To assess the association between usual dietary sodium intake and blood pressure among US children and adolescents, overall and by weight status.
Methods: Children and adolescents aged 8 to 18 years (n = 6235) who participated in NHANES 2003-2008 comprised the sample. Subjects' usual sodium intake was estimated by using multiple 24-hour dietary recalls. Linear or logistic regression was used to examine association between sodium intake and blood pressure or risk for pre-high blood pressure and high blood pressure (pre-HBP/HPB).
Results: Study subjects consumed an average of 3387 mg/day of sodium, and 37% were overweight/obese. Each 1000 mg per day sodium intake was associated with an increased SD score of 0.097 (95% confidence interval [CI] 0.006-0.188, ∼1.0 mm Hg) in systolic blood pressure (SBP) among all subjects and 0.141 (95% CI: -0.010 to 0.298, ∼1.5 mm Hg) increase among overweight/obese subjects. Mean adjusted SBP increased progressively with sodium intake quartile, from 106.2 mm Hg (95% CI: 105.1-107.3) to 108.8 mm Hg (95% CI: 107.5-110.1) overall (P = .010) and from 109.0 mm Hg (95% CI: 107.2-110.8) to 112.8 mm Hg (95% CI: 110.7-114.9; P = .037) among those overweight/obese. Adjusted odds ratios comparing risk for pre-HBP/HPB among subjects in the highest versus lowest sodium intake quartile were 2.0 (95% CI: 0.95-4.1, P = .062) overall and 3.5 (95% CI: 1.3-9.2, P = .013) among those overweight/obese. Sodium intake and weight status appeared to have synergistic effects on risk for pre-HBP/HPB (relative excess risk for interaction = 0.29 (95% CI: 0.01-0.90, P < .05).
Conclusions: Sodium intake is positively associated with SBP and risk for pre-HBP/HPB among US children and adolescents, and this association may be stronger among those who are overweight/obese.