Anti-glycaemic effect of the Chinese modified DASH diet combined with 23% low-sodium salt in patients with hypertension and type 2 diabetes: a clinical trial

Background Although many previous trials have formalized the blood glucose-lowering effect of the DASH diet, relevant reports in China remain limited. This study aimed to explore the anti-hyperglycaemic effect of the Chinese Modified Dietary Approaches to Stop Hypertension diet combined with 23% low-sodium salt and meal packs in patients with hypertension and type 2 diabetes. Methods We conducted a randomized controlled single-blinded trial with a semi-open design; 100 participants were randomly assigned to Group A (control), Group B (23% low-sodium salt), and Group C (meal packs) for 8 weeks of dietary intervention. All participants were followed up weekly to collect glycaemia data (standardized meal tolerance test), salt use, and adverse events. Results Generalized estimating equation analysis indicated that fasting blood glucose decreased in all three groups following the intervention when compared to baseline. Group A decreased by 0.72 mmol/L (P = 0.008), while Groups B and C decreased by 2.02 mmol/L and 2.06 mmol/L, respectively (both P < 0.001). Although the latter two groups experienced greater reductions than Group A, the differences among the groups were not statistically significant (P = 0.450). For postprandial blood glucose, Group C showed the most pronounced decrease. The three groups recorded reductions of 2.43 mmol/L, 2.52 mmol/L, and 4.29 mmol/L, respectively (all P < 0.001), with again no significant difference observed between the groups (P = 0.088). The most notable enhancement in postprandial glucose was observed in Group C, which demonstrated a 51.5% improvement in its control rate. However, there was no statistically significant difference between the groups. No serious adverse events occurred during the trial. Conclusion The CM-DASH diet combined with 23% low-sodium salt and meal packs demonstrates potentially beneficial effects on glycemic control in patients with hypertension and type 2 diabetes. This intervention reduces salt intake and fosters the development of healthy eating habits, thereby contributing to the improvement of patients' blood glucose. However, larger studies are necessary to confirm these findings.