24-Hour Urinary Sodium Excretion Association with Cardiovascular Events: A Systematic Review and Dose-Response Meta-Analysis

Objective The relationship between sodium intake and cardiovascular (CV) events remains unconfirmed. Therefore, we carried out a systematic review and dose-response meta-analysis for evaluating the potential impact of 24-hour sodium excretion on CV risk. Besides, 24-hour sodium excretion was used to replace daily sodium diet intake.Methods We searched ISI Web of Science, Embase, PubMed, and the Cochrane Library. Our study included cohort studies reporting hazard ratio (HR). The random-effects model was used for summarizing the total relative risks (RRs) between the included studies. In addition, the generalized least-squares regression was employed to fit the study model.Results A total of 9 studies involving 645,006 participants were included in this study. A significant non-linear relationship was observed between sodium excretion and CV events (Pnon-linearity< 0.001). In studies collecting 24-h urine samples, the sodium excretion and CV events risk were associated linearly (RR: 1.04; 95% CI: 1.01, 1.07).Conclusion In a linear dose-response manner, every 1 g increase in sodium intake was associated with an increased risk of CV events up to 4%. Further studies are required to validate our conclusions further.