Association of sodium intake and major cardiovascular outcomes: a dose-response meta-analysis of prospective cohort studies

BackgroundThe association of sodium intake with the risk of cardiovascular morbidity and mortality is inconsistent. Thus, the present meta-analysis was conducted to summarize the strength of association between sodium intake and cardiovascular morbidity and mortality.MethodsPubMed, Embase, and the Cochrane Library were searched systematically to identify the relevant studies up to October 2017. The effect estimates for 100mmol/day increase in sodium intake were calculated using 95% confidence intervals (CIs) of cardiac death, total mortality, stroke, or stroke mortality for low (<3g/d), moderate (3-5g/d), or heavy (>5g/d) sodium intake, and minimal sodium intake comparison.ResultsA total of 16 prospective cohort studies reported data on 205,575 individuals. The results suggested that an increase in sodium intake by 100mmol/d demonstrated little or no effect on the risk of cardiac death (P=0.718) and total mortality (P=0.720). However, the risk of stroke incidence (P=0.029) and stroke mortality (P=0.007) was increased significantly by 100mmol/day increment of sodium intake. Furthermore, low sodium intake was associated with an increased risk of cardiac death (P=0.003), while moderate (P<0.001) or heavy (P=0.001) sodium intake was associated with an increased risk of stroke mortality.ConclusionsThese findings suggested that sodium intake by 100mmol/d increment was associated with an increased risk of stroke incidence and stroke mortality. Furthermore, low sodium intake was related to an increased cardiac death risk, while moderate or heavy sodium intake was related to an increased risk of stroke mortality.