title: The effect of potassium supplementation on blood pressure in hypertensive subjects: A systematic review and meta-analysis.
abstract: BACKGROUND
  Several intervention studies have investigated the relation between potassium intake and blood-pressure, particularly in hypertensive subjects. However, uncertainties still exist about the existence and the amount of such an effect, and about the role of some potential effect-modifiers, including the baseline potassium intake and geographical area.
  
  
  METHODS
  We carried out a systematic review of the evidence concerning such relation in hypertensive subjects, performing a meta-analysis and a meta-regression of RCT with selective and validated long-term (≥4weeks) potassium supplementation. We also implemented 'unconventional' search strategies in order to identify all potentially interesting studies.
  
  
  RESULTS
  Overall, potassium supplementation decreased systolic blood pressure of 4.48mmHg (95% CI 3.07-5.90) and diastolic blood pressure of 2.96mmHg (1.10-4.82). There was little evidence of dose-response relation between blood-pressure decrease and potassium supplementation, as assessed through total achieved potassium intake in the intervention groups, difference in achieved potassium intake, and study duration. However, lower (<90mmol/day) potassium intake at baseline was associated with a higher blood-pressure lowering effect, as were higher sodium intake (particularly ≥4g/day), higher sodium-to-potassium ratio and the absence of any anti-hypertensive drug treatment. Trials conducted in Southern Europe showed the highest blood-pressure lowering effect compared with the remaining regions.
  
  
  CONCLUSIONS
  Potassium supplementation in hypertensives was generally associated with decreased blood pressure, particularly in high sodium consumers, subjects not on hypertensive drug treatment, and those in the lowest category of potassium intake. An adequate dietary intake of potassium, in the order of 90mmol/day, should be achieved for blood pressure control.
authors.affiliation: CREAGEN, Environmental, Genetic and Nutritional Epidemiology Research Center, Via Campi 287, 41125 Modena, Italy; Section of Public Health, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Filippini
authors.affiliation: CREAGEN, Environmental, Genetic and Nutritional Epidemiology Research Center, Via Campi 287, 41125 Modena, Italy; Section of Public Health, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Violi
authors.affiliation: Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: D'Amico
authors.affiliation: CREAGEN, Environmental, Genetic and Nutritional Epidemiology Research Center, Via Campi 287, 41125 Modena, Italy; Section of Public Health, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy. Electronic address: marco.vinceti@unimore.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Vinceti
mesh_terms: D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D019587:Dietary Supplements; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D011188:Potassium / Q000008:administration & dosage*
chemical_list: D011188:Potassium
keywords: Blood pressure; Dietary supplement; Hypertension; Meta-analysis; Meta-regression; Potassium; Systematic review