Dietary Sodium Reduction Reduces Albuminuria: A Cluster Randomized Trial

Abstract

Objectives: The objective of the study was to assess the impact of sustained dietary salt reduction on albuminuria in nearly 2000 community-dwelling adults.

Design and methods: The present study is a prespecified secondary analysis of the China Rural Health Initiative Salt Reduction Study cluster randomized trial undertaken in 120 villages in rural China. Villages were randomized to a sodium reduction program of education and access to reduced-sodium salt substitute or control. Urinary albumin-to-creatinine ratio (uACR) and albuminuria (uACR ≥22.1 or 31.0 mg/g for men and women, respectively) were assessed at 18 months in a stratified random sample of predominantly older individuals living in participating rural villages.

Results: A total of 2,566 participants from 119 villages provided 1,903 eligible urine samples. The sodium reduction program reduced sodium intake by an equivalent of 0.82g of salt/day (0.06-1.68 g) (322 [24-661] mg sodium/day). The mean uACR was 8.85 (8.05-9.82) mg/g (1.00 [0.91-1.11] mg/mmol) in intervention participants compared with 10.53 (9.73-11.33) mg/g (1.19 [1.10-1.28] mg/mmol) in control participants (p=0.008). The corresponding odds ratio for albuminuria was 0.67 (0.46-0.99).

Conclusions: Dietary sodium reduction was associated with significantly lower uACR and less albuminuria after 18 months. Whether CKD progression can be slowed by dietary sodium reduction should be a global research priority. CLINICALTRIALS.GOV: NCT01259700.