Using a low-sodium, high-potassium salt substitute to reduce blood pressure among Tibetans with high blood pressure: a patient-blinded randomized controlled trial

PLoS One. 2014 Oct 22;9(10):e110131. doi: 10.1371/journal.pone.0110131. eCollection 2014.

Abstract

Objectives: 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).

Method: 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).

Conclusion: 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.

Trial registration: ClinicalTrials.gov NCT01429246.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Aged
  • Blood Pressure / drug effects
  • Blood Pressure Determination
  • Ethnic Groups
  • Female
  • Humans
  • Hypertension / diet therapy*
  • Hypertension / economics
  • Hypertension / ethnology
  • Hypertension / physiopathology
  • Magnesium Chloride / administration & dosage*
  • Male
  • Middle Aged
  • Potassium Chloride / administration & dosage*
  • Sodium Chloride, Dietary / administration & dosage*
  • Tibet
  • Treatment Outcome

Substances

  • Sodium Chloride, Dietary
  • Magnesium Chloride
  • Potassium Chloride

Associated data

  • ClinicalTrials.gov/NCT01429246