Abstract Body: Background: High sodium intake is a significant risk factor for hypertension and cardiovascular disease. Animal studies have demonstrated that high salt diet promotes tissue inflammation and increases systemic inflammation, such that it is plausible that sodium induced inflammation might be another pathway to hypertension. However, whether the link between dietary sodium intake and systematic inflammation in humans remains unclear due to limited human studies, different designs and inconsistent findings. Therefore, we tested the hypothesis that dietary sodium reduction reduces systemic inflammation in humans by leveraging the randomized controlled trial design of the DASH-Sodium study.
Methods: DASH-Sodium study was a multicenter, randomized trial comparing the effects on blood pressure (BP) of three levels of sodium intake (3450 mg/d, 2300mg/d, and 1150 mg/d) in two diets (DASH vs American) among US adults. Five systematic inflammatory markers including hs-CRP, IFN-γ, IL-6, IL-10, and TNF-α were measured at each study visit in stored plasma samples from 224 participants. Two-level mixed-effects linear regression models were used to assess the effect of sodium reduction on inflammatory markers with adjustment of covariates.
Results: A total of 224 participants (aged 49.4±9.5 yrs, 61% female, 62% black, and 2% other races) from the DASH-Sodium study were included in the analyses. Overall, compared to high sodium group, low sodium group had slightly elevated hs-CRP (p=0.013), and intermediate sodium group had decreased TNF-α (p=0.011). Both significances, however, disappeared after adjusting for multiple testing (p_adjust >0.01).
Conclusion: Modest dietary sodium reduction as recommended did not induce significant changes in systematic inflammation in humans.