Dietary Sodium-Restriction (DIS) and Renal Meals (RM) for Hemodialysis (HD)(DISaRM-HD)

Impact of a Low-Sodium Meal Feeding Protocol on Interdialytic Weight Gain and Markers of Cardiovascular Health in Hemodialysis Patients

Chronic volume overload (VO) is a primary factor responsible for the excessive cardiovascular morbidity and mortality in hemodialysis (HD) patients. VO is caused in part by excessive fluid intake that is secondary to the consumption of a high salt diet. HD patients are often counselled to restrict their dietary sodium intake to help manage thirst and reduce their interdialytic weight gain (IDWG). However, data from recently published investigations demonstrate that dietary counseling alone may be ineffective. The objective of this randomized controlled trial is to determine if short-term feeding of low-sodium meals can "prime" changes in long-term nutrition behavior. It is hypothesized that feeding low-sodium meals for one month will significantly reduce IDWG and related outcomes, and continued dietary counseling and education support for 6 months will result in a sustained reduction in sodium intake upon patient resumption of meal responsibility. HD patients will be recruited and randomized to 2 groups: 1) Low-sodium meal feeding plus dietary counseling; or 2) a weight-list control group that will initially receive dietary counseling alone. IDWG will serve as the primary outcome with fluid volume overload, intradialytic hypotension, cramping, dietary sodium intake, sodium taste sensitivity and preference, and sodium self-efficacy evaluated at 1 and 6 months. This outcomes of this investigation will provide the first data on whether meal provision is an effective tool for dietary modeling and prolonged behavior change in HD patients.

Chronic kidney disease patients with end-stage renal disease require regular hemodialysis (HD) therapy 3-4 days per week to filter their blood of toxins/waste and to remove excess fluid. HD therapy is essential for survival in patients with kidney failure, but the dialysis process is inefficient and does not remove all of the fluid and waste products that accumulate in patients since their last treatment. The inefficiency of dialysis, coupled with excessive dietary sodium and fluid intakes, results in a high prevalence of chronic volume overload (VO) and VO dependent hypertension (HTN). Both VO & HTN can have adverse effects on the heart and arteries, eventually lead to enlargement of the heart and cardiac dysfunction (1-3).

Dialysis care providers (doctors, dietitians, technicians) provide regular counseling for patients to reduce their dietary sodium and fluid intake, despite widespread non-adherence and the high prevalence of both VO and hypertension. Research interventions to increase dietary education and support behavior change have also demonstrated low efficacy in the dialysis patient population. Many barriers and factors contribute to excessive dietary sodium intakes and poor dietary adherence, thus is appears that current dietary education strategies may not be robust enough to change patient behaviors. However, a recent study in heart failure patients demonstrated that home-delivered meals represent a unique opportunity alter outpatient dietary practices. Patients with multiple comorbidities and numerous dietary behaviors, such as those on renal replacement therapy, may need additional support to establish and maintain dietary changes.

The purpose of this study is to compare dietary counseling with renal home meal delivery on clinical outcomes relating to both VO & HTN. This trial is a comparative-effectiveness mixed-models design. In this study, patients will be randomized to one of two study arms: 1) CON (7 months total) where patients receive usual care (eating their normal diet) for the first 5 months of the study. This will be followed by a 2-month period where they will receive home-delivered meals and additional dietary counseling to reduce sodium intake; OR 2) INT (5 months total), where patients will receive home-delivered meals plus additional dietary counseling for the first 2 months of the study, followed by 3 months of continued counseling. During the home-meal delivery periods, participants will be provided a low-sodium/renal diet that includes receiving 2 meals per day during their 1st month, and 1 meal per day during the 2nd month (month 6 and 7 for CON; and month 1 and 2 for INT). The meals will be delivered to the participant's homes each week by momsmeals.com.

We are also plan to collect sensory taste data to characterize patients on dialysis preferences for salt. It is possible that a low sodium diet may change these preferences, so that patients desire more low-sodium tasting food. This information would allow us to analyze how dialysis patients salt intake is associate with taste preference with salt and how this relates to clinical outcomes. The study outcomes include: clinical outcomes (hospitalizations, treatment efficiency), cardiovascular measures (blood pressure, cardiac output, and vascular resistance) and fluid/hydration status (total body water, extracellular fluid) using bioelectrical impedance.

Inclusion Criteria:

1. Willingness to sign informed consent document and age 18 or greater.
2. High fluid gainer/excessive overloaded defined by: > 3.0 % of estimated-dry weight (EDW)
3. No upper or lower limb amputations. This criteria is necessary because the BIS device we are using is not able to provide accurate estimates of fluid status in participants with limb amputations.
4. No pacemakers
5. Willingness to consume intervention meals provided throughout the study.

Exclusion Criteria:

• not meeting above inclusion criteria 1 - 4