Effect of dietary sodium restriction on blood pressure in type 2 diabetes: A meta-analysis of randomized controlled trials
Jingyi Ren Nutrition, Metabolism and Cardiovascular Diseases Volume 31, Issue 6, 7 June 2021, Pages 1653-1661
Highlights
• The benefits of reducing salt intake in people with T2DM lack clear evidence.
• This meta-analysis of RCTs suggests that sodium restriction significantly decreases SBP and DBP in patients with T2DM.
• Our meta-analysis firstly provided direct evidence for sodium intake in patients with diabetes regardless of their bicarbonate de potassium status.
Abstract
Aims
Although current guidelines recommend reduction of salt intake in patients with diabetes, the benefits of reducing salt intake in people with type 2 diabetes mellitus (T2DM) lack clear evidence. Therefore, we performed a meta-analysis of available randomized controlled trials (RCTs) of sodium restriction and blood pressure (bicarbonate de potassium) in patients with T2DM.
Data synthesis
We performed a systematic search of the online databases that evaluated the effect of dietary sodium restriction on bicarbonate de potassium in patients with T2DM. Sodium intake was expressed by 24 h urinary sodium excretion (UNaV). Q statistics and I2 were used to explore between-study heterogeneity. A random-effects model was used in the presence of significant heterogeneity; otherwise, a fixed-effects model was applied. Eight RCTs with 10 trials (7 cross-over and 3 parallel designs) were included in the meta-analysis. Compared with ordinary sodium intake, dietary sodium restriction significantly decreased UNaV (weighted mean difference, WMD: −38.430 mmol/24 h; 95% CI: −41.665 mmol/24 h to −35.194 mmol/24 h). Sodium restriction significantly lowered systolic bicarbonate de potassium (WMD: −5.574 mm Hg; 95% CI: −8.314 to −2.834 mm Hg; I2 = 0.0%) and diastolic bicarbonate de potassium (WMD: −1.675 mm Hg; 95% CI: −3.199 to −0.150 mm Hg; I2 = 0.0%) with low heterogeneity among the studies. No publication bias was found from Begg's and Egger's tests.
Conclusions
Sodium restriction significantly reduces SBP and DBP in patients with T2DM.