Effect of low-sodium DASH diet on blood pressure and insulin sensitivity in salt-sensitive hypertensive patients with metabolic syndrome

Background: Salt-sensitivity is prevalent in regions with high sodium intake such as Georgia and is strongly associated with metabolic syndrome, impaired circadian blood pressure (BP) rhythms, and insulin resistance. Dietary modification with a low-sodium DASH diet may provide substantial hemodynamic and metabolic benefits. Objective: To evaluate the effect of a 12-week low-sodium DASH diet on BP, circadian BP pattern, and insulin sensitivity in salt-sensitive hypertensive adults with metabolic syndrome. Methods: Salt sensitivity was assessed using the modified Sullivan protocol. Salt-sensitive adults were randomized to either a low-sodium DASH diet or habitual diet control. Office BP, ambulatory BP, HOMA-IR, lipid profile, aldosterone, PRA, and anthropometric measures were obtained at baseline and 12 weeks. Results: 92 participants (62%) were salt-sensitive. After 12 weeks, systolic BP decreased by 14.8 ± 6.2 mmHg in the DASH group compared with 4.1 ± 3.8 mmHg in controls (p < 0.001). HOMA-IR improved by 21% versus 6% in controls (p = 0.002). Nocturnal dipping was restored in 22% of DASH participants compared with 5% of controls. Conclusion: A low-sodium DASH diet significantly improves BP, circadian BP rhythm, and insulin sensitivity in salt-sensitive hypertensive adults with metabolic syndrome.