Pilot feasibility study examining the effects of a comprehensive volume reduction protocol on hydration status and blood pressure in hemodialysis patients

OUP accepted manuscript

Patients on chronic hemodialysis are counseled to reduce dietary sodium intake to limit their thirst and consequent interdialytic weight gain (IDWG), chronic volume overload and hypertension. Low-sodium dietary trials in hemodialysis are sparse and mostly indicate that dietary education and behavioral counseling are ineffective in reducing sodium intake and IDWG. Additional nutritional restrictions and numerous barriers further complicate dietary adherence. A low-sodium diet may also reduce tissue sodium, which is positively associated with hypertension and left ventricular hypertrophy. A potential alternative or complementary approach to dietary counseling is home delivery of low-sodium meals. Low-sodium meal delivery has demonstrated benefits in patients with hypertension and congestive heart failure but has not been explored or implemented in patients undergoing hemodialysis. The objective of this review is to summarize current strategies to improve volume overload and provide a rationale for low-sodium meal delivery as a novel method to reduce volume-dependent hypertension and tissue sodium accumulation while improving quality of life and other clinical outcomes in patients undergoing hemodialysis.

Pilot study to reduce interdialytic weight gain by provision of low-sodium, home-delivered meals in hemodialysis patients

INTRODUCTION

Patients with kidney failure undergoing maintenance hemodialysis (HD) therapy are routinely counseled to reduce dietary sodium intake to ameliorate sodium retention, volume overload, and hypertension. However, low-sodium diet trials in HD are sparse and indicate that dietary education and behavioral counseling are ineffective in reducing sodium intake. This study aimed to determine whether 4 weeks of low-sodium, home-delivered meals in HD patients reduces interdialytic weight gain (IDWG). Secondary outcomes included changes in dietary sodium intake, thirst, xerostomia, blood pressure, volume overload, and muscle sodium concentration.

METHODS

Twenty HD patients (55 ± 12 years, body mass index [BMI] 40.7 ± 16.6 kg/m² ) were enrolled in this study. Participants followed a usual (control) diet for the first 4 weeks followed by 4 weeks of three low-sodium, home-delivered meals per day. We measured IDWG, hydration status (bioimpedance), standardized blood pressure (BP), food intake (3-day dietary recall), and muscle sodium (magnetic resonance imaging) at baseline (0 M), after the 4-week period of usual diet (1 M), and after the meal intervention (2 M).

FINDINGS

The low-sodium meal intervention significantly reduced IDWG when compared to the control period (-0.82 ± 0.14 kg; 95% confidence interval, -0.55 to -1.08 kg; P < 0.001). There were also 1 month (1 M) to 2 month (2 M) reductions in dietary sodium intake (-1687 ± 297 mg; P < 0.001); thirst score (-4.4 ± 1.3; P = 0.003), xerostomia score (-6.7 ± 1.9; P = 0.002), SBP (-18.0 ± 3.6 mmHg; P < 0.001), DBP (-5.9 ± 2.0 mmHg; P = 0.008), and plasma phosphorus -1.55 ± 0.21 mg/dL; P = 0.005), as well as a 0 M to 2 M reduction in absolute volume overload (-1.08 ± 0.33 L; P = 0.025). However, there were no significant changes in serum or tissue sodium (all P > 0.05).

DISCUSSION

Low-sodium, home-meal delivery appears to be an effective method for improving volume control and blood pressure in HD patients. Future studies with larger sample sizes are needed to examine the long-term effects of home-delivered meals on these outcomes and to assess cost-effectiveness.