title: Compared with usual sodium intake, low- and excessive-sodium diets are associated with increased mortality: a meta-analysis.
abstract: BACKGROUND
  The effect of sodium intake on population health remains controversial. The objective was to investigate the incidence of all-cause mortality (ACM) and cardiovascular disease events (CVDEs) in populations exposed to dietary intakes of low sodium (<115 mmol), usual sodium (low usual sodium: 115-165 mmol; high usual sodium: 166-215 mmol), and high sodium (>215 mmol).
  
  
  METHODS
  The relationship between individual measures of dietary sodium intake vs. outcome in cohort studies and randomized controlled trials (RCTs) measured as hazard ratios (HRs) were integrated in meta-analyses.
  
  
  RESULTS
  No RCTs in healthy population samples were identified. Data from 23 cohort studies and 2 follow-up studies of RCTs (n = 274,683) showed that the risks of ACM and CVDEs were decreased in usual sodium vs. low sodium intake (ACM: HR = 0.91, 95% confidence interval (CI) = 0.82-0.99; CVDEs: HR = 0.90, 95% CI = 0.82-0.99) and increased in high sodium vs. usual sodium intake (ACM: HR = 1.16, 95% CI = 1.03-1.30; CVDEs: HR = 1.12, 95% CI = 1.02-1.24). In population representative samples adjusted for multiple confounders, the HR for ACM was consistently decreased in usual sodium vs. low sodium intake (HR = 0.86; 95% CI = 0.81-0.92), but not increased in high sodium vs. usual sodium intake (HR = 1.04; 95% CI = 0.91-1.18). Within the usual sodium intake range, the number of events was stable (high usual sodium vs. low usual sodium: HR = 0.98; 95% CI = 0.92-1.03).
  
  
  CONCLUSIONS
  Both low sodium intakes and high sodium intakes are associated with increased mortality, consistent with a U-shaped association between sodium intake and health outcomes.
authors.affiliation: Department of Rheumatology IR4242, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. graudal@dadlnet.dk.
authors.forename: Niels
authors.initials: N
authors.lastname: Graudal
authors.affiliation: Department of Clinical Pharmacology, Bispebjerg University Hospital, Copenhagen Denmark.
authors.forename: Gesche
authors.initials: G
authors.lastname: Jürgens
authors.affiliation: Department of Rheumatology IR4242, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Bo
authors.initials: B
authors.lastname: Baslund
authors.affiliation: Albert Einstein College of Medicine, New York.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Alderman
mesh_terms: D001794:Blood Pressure; D016009:Chi-Square Distribution; D004039:Diet, Sodium-Restricted / Q000009:adverse effects / Q000401:mortality*; D018572:Disease-Free Survival; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000209:etiology / Q000401:mortality* / Q000503:physiopathology; D016017:Odds Ratio; D064167:Recommended Dietary Allowances; D018570:Risk Assessment; D012307:Risk Factors; D017673:Sodium Chloride, Dietary / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D017673:Sodium Chloride, Dietary
keywords: blood pressure; cardiovascular disease; diet; hypertension; meta-analysis; mortality; salt; sodium chloride; stroke.