China Salt Substitute Study - CSSS

Background

Lower levels of dietary sodium and higher levels of dietary potassium are associated with lower blood pressure. There are, however, few proven, practical and low cost strategies for control of blood pressure by modification of these dietary cations. Rural northern China, where salt consumption is very high and most foods are prepared at home, may be particularly suited to blood pressure control with a strategy based on a salt substitute.

Methods

The China Salt Substitute Study was a randomised, controlled trial designed to establish the long-term effects of a low-sodium, high-potassium salt substitute (65% sodium chloride, 25% potassium chloride, 10% magnesium sulphate) compared to normal salt (100% sodium chloride) on blood pressure among high-risk individuals living in rural northern China. Individuals were assigned at random in a double blind design to replace their usual household salt supply with either study salt substitute or study salt for a 12 month period.

Results

The mean age of the 608 randomised participants was 60 and 56% were female. 64% had a baseline history of vascular disease and 61% were using one or more blood pressure lowering drugs. Mean baseline blood pressure was 159/93 mmHg (SD 26/14). At 12 months the mean systolic blood pressure was 5.4 mmHg (95%CI 2.3 to 8.5) lower in the salt substitute group compared to the normal salt group (p =0.001). The magnitude of the systolic blood pressure reduction grew progressively during follow-up (p =0.001). No effect of the salt substitute on diastolic blood pressure was detected.

Conclusions

Salt substitution is a simple, low-cost intervention that can produce a substantial and sustained blood pressure reduction in this setting. A population-wide switch to salt substitute in rural China would be expected to prevent many hundreds of thousands of vascular events each year.

Institute Investigators

Project managers:

  • Nicole Li
  • Dorothy Han

Collaborators

Funding Agencies

  • The study is partly funded by the University of Sydney
  • Fu Wai Hospital, China

Enquiries regarding the salt substitute should be directed to Mr Graham Lawrence (Director, Commercial Development) on 02 9993 4583 or email glawrence@george.org.au.