Assessment of the Clinical Outcomes of Sodium and Fluid-Restricted Diets on Blood Pressure and Volume Status in CKD Patients

Abstract

Background: Chronic kidney disease (CKD) is a progressive disorder associated with hypertension and volume overload, where sodium and fluid restriction play vital roles in clinical management. Objective: This study investigates the clinical impact of sodium and fluid-restricted diets on blood pressure control and extracellular volume status among CKD patients, with particular focus on statistical associations and measurable outcomes. Methods: A prospective cohort study was conducted at the Department of Nephrology, Rajshahi Medical College, Bangladesh, between January 2022 and December 2023. Ninety-six CKD patients (stages 3–5) were enrolled. Participants were stratified into sodium-restricted (<2 g/day) and moderate sodium intake (>2 g/day) groups with individualized fluid restriction. Clinical outcomes included systolic and diastolic blood pressure, interdialytic weight gain, and extracellular water by bioimpedance. Results: Mean systolic blood pressure decreased significantly in the restricted group from 154.8 ± 12.4 mmHg to 138.6 ± 10.2 mmHg (p <0.001), compared with 152.3 ± 11.7 mmHg to 147.9 ± 9.8 mmHg in controls (p =0.041). Diastolic pressure declined by 10.7% in the intervention group versus 3.2% in controls. Interdialytic weight gain reduced by 1.3 ± 0.4 kg (23.5%) compared with 0.5 ± 0.3 kg (8.7%) in controls (p <0.001). Extracellular water declined from 18.9 ± 3.2 L to 16.8 ± 2.6 L in restricted patients (11.1% reduction), versus 19.1 ± 2.9 L to 18.4 ± 2.5 L (3.7% reduction) in controls (p =0.002). Conclusion: Sodium and fluid restriction significantly improve blood pressure control and volume status in CKD patients, suggesting integration of dietary interventions into standard management can reduce cardiovascular and renal progression risks.