title: Relationship between sodium and potassium intake and blood pressure in a sample of overweight adults.
abstract: OBJECTIVE
  The aim of this study was to examine the relationship between sodium and potassium intakes and blood pressure (BP) in a clinical sample.
  
  
  METHODS
  Secondary analysis of baseline data from 328 participants (mean age: 43.6 ± 8 y, mean body mass index [BMI]: 32.4 ± 4.2 kg/m2, mean systolic BP [SBP]/diastolic BP [DBP]: 124.9 ± 14.5/73.3 ± 9.9 mm Hg) of the 12-mo HealthTrack randomized controlled weight loss trial was conducted. Resting BP and 24-h urine sodium and potassium were measured. Dietary intake was evaluated with 4-d food records and self-reported diet histories.
  
  
  RESULTS
  Urinary sodium was positively correlated (Spearman's rho) with SBP (r = 0.176; P = 0.001) and DBP (r = 0.150; P = 0.003). The ratio of sodium to potassium was positively correlated with SBP (r = 0.1; P = 0.035). Urinary sodium (F [4,323] = 20.381; P < 0.0005; adjusted R2= 0.231) and sodium-to-potassium ratio (F[4,323] = 25.008; P < 0.0005; adjusted R2= 0.227) significantly predicted SBP after controlling for age, sex, BMI, and hypertension medication use. Dietary sodium and potassium significantly predicted urinary sodium (B = 0.33, t = 4.032, P < 0.01) and potassium (B = 0.67, t = 8.537, P < 0.01) excretion, respectively, after adjustment for energy and BMI. Median dietary sodium intake was 3197 mg/d and median dietary potassium intake was 2886 mg/d. Cereal-based products and dishes were the major contributors (22%) to total sodium intake.
  
  
  CONCLUSIONS
  In the present study, a high dietary sodium intake and high sodium-to-potassium ratio predicted high SBP. This suggests a need to focus dietary advice on reduction of sources of sodium and increasing sources of potassium in weight loss interventions to improve BP control.
authors.affiliation: School of Medicine, University of Wollongong, Northfields Avenue, Wollongong, NSW, Australia. Electronic address: rnn954@uowmail.edu.au.
authors.forename: Rhoda N
authors.initials: RN
authors.lastname: Ndanuko
authors.affiliation: School of Medicine, University of Wollongong, Northfields Avenue, Wollongong, NSW, Australia.
authors.forename: Linda C
authors.initials: LC
authors.lastname: Tapsell
authors.affiliation: School of Medicine, University of Wollongong, Northfields Avenue, Wollongong, NSW, Australia.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Charlton
authors.affiliation: School of Medicine, University of Wollongong, Northfields Avenue, Wollongong, NSW, Australia.
authors.forename: Elizabeth P
authors.initials: EP
authors.lastname: Neale
authors.affiliation: School of Medicine, University of Wollongong, Northfields Avenue, Wollongong, NSW, Australia.
authors.forename: Katrina M
authors.initials: KM
authors.lastname: O'Donnell
authors.affiliation: Statistical Consulting Service, School of Mathematics and Applied Statistics, University of Wollongong, Wollongong, NSW, Australia.
authors.forename: Marijka J
authors.initials: MJ
authors.lastname: Batterham
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003296:Cooking; D003430:Cross-Sectional Studies; D015930:Diet Records; D000072001:Diet, Healthy / Q000208:ethnology; D002523:Edible Grain / Q000009:adverse effects / Q000737:chemistry; D057140:Fast Foods / Q000009:adverse effects / Q000032:analysis; D005260:Female; D006801:Humans; D006973:Hypertension / Q000208:ethnology / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009517:New South Wales; D009765:Obesity / Q000208:ethnology / Q000503:physiopathology* / Q000652:urine; D050177:Overweight / Q000208:ethnology / Q000503:physiopathology* / Q000652:urine; D010349:Patient Compliance / Q000208:ethnology; D011188:Potassium / Q000652:urine; D017419:Potassium, Dietary / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use*; D057566:Self Report; D012964:Sodium / Q000652:urine; D012982:Sodium, Dietary / Q000008:administration & dosage / Q000009:adverse effects* / Q000032:analysis
chemical_list: D017419:Potassium, Dietary; D012982:Sodium, Dietary; D012964:Sodium; D011188:Potassium
keywords: Blood pressure; Food sources; Obese; Potassium; Sodium; Urinary excretion