title: Using a low-sodium, high-potassium salt substitute to reduce blood pressure among Tibetans with high blood pressure: a patient-blinded randomized controlled trial.
abstract: OBJECTIVE
  To evaluate the effects of a low-sodium and high-potassium salt-substitute on lowering blood pressure (BP) among Tibetans living at high altitude (4300 meters).
  
  
  METHODS
  The study was a patient-blinded randomized controlled trial conducted between February and May 2009 in Dangxiong County, Tibetan Autonomous Region, China. A total of 282 Tibetans aged 40 or older with known hypertension (systolic BP≥140 mmHg) were recruited and randomized to intervention (salt-substitute, 65% sodium chloride, 25% potassium chloride and 10% magnesium sulfate) or control (100% sodium chloride) in a 1: 1 allocation ratio with three months' supply. Primary outcome was defined as the change in BP levels measured from baseline to followed-up with an automated sphygmomanometer. Per protocol (PP) and intention to treat (ITT) analyses were conducted.
  
  
  RESULTS
  After the three months' intervention period, the net reduction in SBP/DBP in the intervention group in comparison to the control group was -8.2/-3.4 mmHg (all p<0.05) in PP analysis, after adjusting for baseline BP and other variables. ITT analysis showed the net reduction in SBP/DBP at -7.6/-3.5 mmHg with multiple imputations (all p<0.05). Furthermore, the whole distribution of blood pressure showed an overall decline in SBP/DBP and the proportion of patients with BP under control (SBP/DBP<140 mmHg) was significantly higher in salt-substitute group in comparison to the regular salt group (19.2% vs. 8.8%, p = 0.027).
  
  
  CONCLUSIONS
  Low sodium high potassium salt-substitute is effective in lowering both systolic and diastolic blood pressure and offers a simple, low-cost approach for hypertension control among Tibetans in China.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01429246.
authors.affiliation: Department of Cardiology, Beijing Jishuitan Hospital, 4th medical college of Peking University, Beijing, China.
authors.forename: Xingshan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: The George Institute for Global Health at Peking University Health Science Center, Beijing, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Yin
authors.affiliation: The George Institute for Global Health at Peking University Health Science Center, Beijing, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Li
authors.affiliation: The George Institute for Global Health at Peking University Health Science Center, Beijing, China,; Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America.
authors.forename: Lijing L
authors.initials: LL
authors.lastname: Yan
authors.affiliation: Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Lam
authors.affiliation: The George Institute for Global Health at Peking University Health Science Center, Beijing, China.
authors.forename: Shenshen
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Cardiology, Beijing Jishuitan Hospital, 4th medical college of Peking University, Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.affiliation: Department of Epidemiology and Biostatistics, Peking University School of Public Health, Beijing, China.
authors.forename: Wuxiang
authors.initials: W
authors.lastname: Xie
authors.affiliation: Dangxiong People's Hospital, Tibet, China.
authors.forename: Ba
authors.initials: B
authors.lastname: Sang
authors.affiliation: Tibet Autonomous Region People's Hospital, Tibet, China.
authors.forename: Gesang
authors.initials: G
authors.lastname: Luobu
authors.affiliation: The George Institute for Global Health at Peking University Health Science Center, Beijing, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Ke
authors.affiliation: The George Institute for Global Health at Peking University Health Science Center, Beijing, China,; Department of Epidemiology and Biostatistics, Peking University School of Public Health, Beijing, China.
authors.forename: Yangfeng
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000284:Administration, Oral; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D001795:Blood Pressure Determination; D005006:Ethnicity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000191:economics / Q000208:ethnology / Q000503:physiopathology; D015636:Magnesium Chloride / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D011189:Potassium Chloride / Q000008:administration & dosage*; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*; D018609:Tibet; D016896:Treatment Outcome
chemical_list: D017673:Sodium Chloride, Dietary; D015636:Magnesium Chloride; D011189:Potassium Chloride