A systematic review of the effects of sodium reduction on glucose levels

Abstract

OBJECTIVEAssess effects of sodium reduction on glucose levels.METHODSWe systematically searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, and Web of Science through July 2012. We initially included randomized and non‐randomized intervention trials comparing ≥2 sodium intake levels and examining ≥1 measure of glucose levels.RESULTSOf 2920 abstracts screened, 37 trials (1402 participants) evaluated the effects of sodium intake on glucose levels. Participants were 10–79 years old, primarily healthy or with hypertension. Metaanalysis of 10 randomized, cross‐over trials with ≥7 day interventions, >;80% follow‐up, and intent‐to‐treat analysis of follow‐up fasting glucose concentrations, showed that fasting glucose did not differ by sodium intake (N=299, mean difference, mmol/L: 0.04; 95% confidence interval −0.07,0.14) and heterogeneity was not significant (I2=0%, P=1.0) in the random effects model. Among these studies, mean excretion for the lowest sodium reduction group ranged from 280–2875 mg/d (weighted mean=713 mg/d) versus 2171–6859 mg/d (weighted mean= 5723 mg/d) for the other group.CONCLUSIONOur meta‐analysis of randomized, cross‐over trials, with fasting glucose and low risk of bias, suggests ≥7 day sodium reduction (weighted mean ‐5010 mg/d) does not affect fasting glucose. Variation in methods precluded meta‐analysis of other glucose measures.