Intervention to Reduce Dietary Sodium in Hemodialysis

Cardiovascular disease is the single most common cause of death in hemodialysis (HD) patients. Most HD patients have left ventricular hypertrophy(LVH), a significant predictor of death in this population. LVH is related to extracellular volume expansion and hypertension, both of which are amenable to dietary sodium restriction. However, dietary change is widely known to be difficult to achieve and sustain. Controlling dietary sodium is particularly difficult for HD because many foods are naturally high in sodium, and most prepared/prepackaged foods have significant amounts of sodium added to enhance taste and shelf-life. Research on behavioral methods that are effective in reducing dietary sodium intake in HD is very limited. The purpose of this study is to test, in a randomized clinical trial of 200 HD patients, a behavioral intervention, paired with personal digital assistant (PDA)-based dietary self-monitoring, to enhance adherence to dietary sodium restrictions. Specifically the investigators will: (a) Assess the impact of the intervention on average daily interdialytic weight gains (IDWG-A). (b) Examine the impact of the intervention on self-reported dietary sodium intake. The study hypotheses are that compared to the control group, the intervention group will: (1) demonstrate a statistically significant decline in IDWG-A over the 4-month intervention period, and (2) experience a greater decline in dietary sodium intake. Secondarily, the investigators will explore the impact of the intervention on: (a) pre-dialysis pulse pressure and mean arterial blood pressure, (b) hemodialysis dietary self-efficacy, and (c) intradialytic and postdialytic symptoms and general health-related quality of life. In addition, the investigators will characterize the barriers/facilitators to adherence to the HD dietary regimen and patient experience of the intervention through the use of qualitative methods. The intervention is based on Social Cognitive Theory (SCT). Self-monitoring within the context of the intervention is operationalized as PDA-based dietary recording using BalanceLog software. Participants randomized to the attention control will receive computerized dietary education. Attention control participants will be offered an abbreviated version of the intervention after the 4-month study period concludes. Differences in IDWG-A, pulse pressure, and mean arterial pressure will be examined using a random intercept linear regression modeling. Self-reported dietary sodium, self-efficacy, symptoms, and quality of life will be assessed at baseline, 6 weeks, and 4 month and differences will be examined using repeated measures modeling using GEE. Qualitative analysis of narrative data will be performed.