Eating during treatment can be a cost-effective way to improve outcomes: a letter to the editor.

We read with interest the article by De and Xiang Ai on restricting nutrition during hemodialysis (HD) treatment (De & Xiang Ai, 2015). Given the large number of HD patients who are malnourished, this is an important topic for discussion. We agree with the authors that this remains a controversial topic within the field of nephrology. Certainly, a number of concerns such as postprandial hemodynamics, gastrointestinal symptoms, treatment efficiency, spills/pests, and clinician workload have been raised in the past (Kalantar-Zadeh & Ikizler, 2013; Kinnel, 2005; Kistler, Benner, et al., 2014; Kistler, Fitschen, Ikizler, & Wilund, 2014). A number of these concerns associated with eating during treatment have been examined in the published literature. We believe that highlighting these data, as well as the literature on the benefits of eating during treatment could further the discussion on this topic.Nutritional status is among the strongest predictors of mortality in patients undergoing maintenance HD. This relationship is consistent across a wide range of nutritional markers including dietary intake (Shinaberger et al., 2006), biochemical measures (Kalantar-Zadeh et al., 2005), and nutritional reserve such as lean or fat mass (Kalantar-Zadeh & Kopple, 2006). HD patients have reduced dietary intake on treatment days (Burrowes et al., 2003), and providing nutritional supplements or allowing patients to eat during a single treatment has been shown to help increase dietary intake (Burrowes et al., 2003), prevent muscle catabolism (Pupim, Majchrzak, Flakoll, & Ikizler, 2006), and reduce in fl ammation (Tomayko, Kistler, Fitschen, & Wilund, 2014). When this practice is continued for extended periods of time it leads to improved nutritional status (Caglar et al., 2002), physical function (Tomayko et al., 2014), and quality of life (Scott et al., 2009). All of these factors may contribute to the significant reduction (~30%) in mortality in malnourished patients receiving oral nutrition during their treatment (Lacson, Wang, Zebrowski, Wingard, & Hakim, 2012b; Weiner et al., 2013).Despite these benefits, the authors are correct to point out there are a number of potential concerns related to eating during HD treatment including reduced solute removal, spills/pests, aspiration, and infection control. When we surveyed an international cohort who allowed their patients to eat during treatment about these issues, we found that many of these concerns were not frequently observed in practice (Kistler, Benner, et al., 2014). In fact, reduced solute removal (93.3%), spills/pests (67.4%), and infection control issues (91.3%) were 'never' witnessed in the vast majority of clinics. Furthermore, providing oral supplements during treatment has been shown to reduce overall hospitalizations (Lacson, Ikizler, Lazarus, Teng, & Hakim, 2007; Lacson, Wang, Zebrowski, Wingard, & Hakim, 2012a), of which up to a quarter may be attributable to infection-related causes (Collins et al., 2014).Hemodynamic alterations are the most cited complication associated with eating during HD treatment (Kistler, Benner, et al., 2014). While many hypotensive episodes may be anecdotally attributed to intradialytic eating, up to 40% of all treatments may result in hypotension (Davenport, 2006; Davenport, Cox, & Thuraisingham, 2008); therefore, it is difficult to determine the cause of hypotension without a randomized comparison. When we recently reviewed eight papers examining the effects of eating during HD on blood pressure and blood flow throughout the treatment, we concluded that eating generally led to a transient reduction in blood pressure that was usually not associated with symptoms (Kistler, Fitschen, et al., 2014). An important caveat to this literature is that most of these studies enrolled patients who were hemodynamically stable. Therefore, additional work is needed to identify patients who may be prone to suffering a postprandial drop in blood pressure and to determine the effect intradialytic eating has on central blood pressures and tissue perfusion. …