Monitoring of Dietary Sodium Intake by Salt-Meter Decreases Serum Sodium and Blood Pressure in Patients on Hemodialysis

Background: Excessive sodium intake increases the extracellular fluid volume and osmolarity in hemodialysis patients. This study aimed to investigate the efficacy of self-monitoring of sodium intake by using salt meter and nutrition education in HD patients. Methods: A quasi-experimental study was conducted at Ramathibodi Hospital in Bangkok, Thailand, during July 2023 to February 2024. Hemodialysis patients were randomized to receive intensive dietary education in combination with dietary diary and salt meter for 8 weeks (group A) or standard dietary education alone (group B). Body composition and sodium-related outcomes were measured at baseline, 8 and 16 weeks after recruitment. Results: 46 patients were enrolled, 21 in group A and 25 in group B. The mean age was 64.8 years, and 52.2% were males. Mean baseline interdialytic weight gain (IDWG) was 3.6 kg, mean SBP and DBP were 153.9 and 74.8 mmHg, respectively. Mean IDWG in group A were stable from baseline to 16 weeks whereas mean IDWG in group B increased from baseline by 0.9 and 1.2 kg at 8 and 16 weeks, respectively (p<0.05). At 16 weeks, mean SBP of participants in group A decreased by 9.7 mmHg from baseline (p<0.05). Group B's mean SBP increased by 10.7 mmHg at 8 weeks and 13.7 mmHg at 16 weeks (p<0.05). The trends were similar for DBP. Serum sodium levels in group A decreased from baseline by 1.8 mmol/L at 8 weeks (p<0.01). Interestingly, at 16 weeks, participants in group A had significantly less %BF and more %FFM compared to baseline. Conclusion: The use of salt meter and intensive dietary education for self-monitoring sodium intake for 8 weeks was more effective in controlling blood pressure than standard education alone. Decreased serum sodium levels while applying the intervention demonstrated adherence to less salt intake. A salt meter and dietary diary should be considered to control sodium consumption in hemodialysis patients. Funding: Other NIH Support - Ramathibodi Hospital