A Web-Based Self-management Sodium Intervention in Individuals With CKD

Related Article, p. 847 Related Article, p. 847 The management of dietary sodium intake in individuals with chronic kidney disease (CKD) is of clinical and public health significance for multiple reasons. First, ~10% of the population worldwide has CKD,1Global Burden of Disease 2013 Mortality and Causes of Death CollaboratorsGlobal, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.Lancet. 2015; 385: 117-171Abstract Full Text Full Text PDF PubMed Scopus (5400) Google Scholar and CKD’s ranking as a cause of death globally increased from number 27 in 1990 to number 18 in 2010.2Jha V. Garcia-Garcia G. Iseki K. et al.Chronic kidney disease: global dimension and perspectives.Lancet. 2013; 382: 260-272Abstract Full Text Full Text PDF PubMed Scopus (2599) Google Scholar Second, the costs associated with CKD are staggering; in the United States, treatment costs exceed $48 billion per year,3Centers for Disease Control Chronic Kidney Disease Initiative.https://www.cdc.gov/kidneydisease/basics.htmlDate accessed: December 1, 2019Google Scholar and in the Netherlands, the annual per-patient cost for hemodialysis is $83,736.4Mushi L. Marschall P. Steffen F. The cost of dialysis in low- and middle income countries: a systematic review.BMC Health Serv Res. 2015; 15: 506Crossref PubMed Scopus (66) Google Scholar Furthermore, the potential health consequences of high sodium intake are more common in those with CKD and include higher blood pressure (BP), fluid retention, and increased risk for cardiovascular disease. Although clinical trials of sodium reduction in patients with CKD are limited in size and number, data suggest that sodium reduction lowers fluid volume, body weight, proteinuria, and albuminuria5McMahon E. Bauer J. Hawley C.M. et al.A randomized trial of dietary sodium restriction in CKD.J Am Soc Nephrol. 2013; 24: 2096-2103Crossref PubMed Scopus (208) Google Scholar and positively affects central BP, urinary protein-creatinine ratio, urinary albumin-creatinine ratio, N-terminal pro-brain natriuretic peptide levels, and extracellular to intracellular fluid ratio.6Campbell K.L. Johnson D.W. Bauer J.D. et al.A randomized trial of sodium-restriction on kidney function, fluid volume and adipokines in CKD patients.BMC Nephrol. 2014; 15: 57Crossref PubMed Scopus (39) Google Scholar In this issue of AJKD, Humalda et al7Humalda J.K. Klaassen G. de Vries H. et al.on behalf of the SUBLIME investigatorsA self-management approach for dietary sodium restriction in patients with CKD: a randomized controlled trial.Am J Kidney Dis. 2020; 75: 847-856Abstract Full Text Full Text PDF Scopus (25) Google Scholar report findings from The Sodium Burden Lowered by Lifestyle Intervention: Self-management and E-Health Technology (SUBLIME) Study, which examined the effects of a web-based self-management sodium intervention on 24-hour urinary sodium excretion during a 3-month intervention followed by a 6-month maintenance period. Secondary outcomes of interest were BP, proteinuria, costs, quality of life, self-management skills, and barriers and facilitators for implementation.7Humalda J.K. Klaassen G. de Vries H. et al.on behalf of the SUBLIME investigatorsA self-management approach for dietary sodium restriction in patients with CKD: a randomized controlled trial.Am J Kidney Dis. 2020; 75: 847-856Abstract Full Text Full Text PDF Scopus (25) Google Scholar The study is timely because there are a growing number of mobile apps available for patients with CKD to monitor fluids, weight, BP,8National Kidney FoundationH2OVERLOAD: fluid control for heart-kidney health.https://www.kidney.org/apps/patients/h2overload-fluid-control-heart-kidney-healthDate accessed: December 1, 2019Google Scholar and other nutritional parameters.9Kidney International–NephCureHelpful mobile apps – diet and nutrition.https://nephcure.org/livingwithkidneydisease/managing-your-care/kidney-health-tracking-tools/helpful-mobile-apps/Date accessed: December 1, 2019Google Scholar Data from the only other study we know of that tested a web-based diet intervention in patients with CKD showed app-supported telecounseling with a registered dietitian to be a feasible and well-accepted strategy to improve dietary quality and improve cardiovascular risk factors in early kidney disease.10Chang A. Collins C. Moser M. et al.FitKidney. Remote dietary counseling to reduce sodium intake in patients with stages 1-3a chronic kidney disease: a mixed methods feasibility study.J Ren Nutr. 2020; 30: 53-60Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar As such, the work from Humalda et al addresses an important research gap about pragmatic mechanisms to deliver efficacious cost-efficient diet and lifestyle interventions that are sustainable. The SUBLIME Study recruited from 4 Dutch nephrology clinics and enrolled adults with hypertension and CKD. Clinical characteristics of participants largely reflect the typical patient population of renal clinics, though with a higher proportion of men. Participants in the intervention arm (n = 52) received routine care plus 3 months of intensive intervention involving contact with a coach by telephone/e-mail (e-coaching), with a minimum of 2 individual coaching sessions. Participants were given access to a web-based self-management program dedicated to sodium reduction and were supported by certified lifestyle coaches. During the 6-month maintenance phase, the intervention group completed web-based self-management modules and up to 4 individual e-coaching sessions. The control arm (n = 47) was described simply as having received “routine care.” After the 3-month intervention phase, a 24.8-mmol/d (570-mg/d) mean difference in urinary sodium excretion was observed between the intervention and control groups, reaching borderline statistical significance (P = 0.049). In study planning, the investigators used the treatment effect seen in the ESMO (Effects of Self-monitoring on Outcome of Chronic Kidney Disease) Study (urinary sodium excretion of 30.3 mmol/d [696.9 mg/d]) but this was an overestimation of the between-group mean difference they would actually observe. Notably, the control group had a minimal, though not statistically significant, decline in urinary sodium excretion. After the 3-month intervention, there was also a highly significant decline in systolic BP (SBP; 8 mm Hg) within the intervention group. At the end of the 9-month study period, 24-hour urinary sodium excretion declined in both groups, with ultimately no statistically significant mean difference between them. SBP increased slightly in the intervention group yet continued to decrease slightly in the control group, resulting in a nonsignificant mean difference of 4.3 mm Hg at 9 months. A large initial decrease in sodium excretion in the intervention group during the 3-month intervention phase may have played a role in the slight, but not statistically significant, difference in SBP between the groups (132 vs 135 mm Hg). Notably, these values were still lower than the baseline SBPs of 140 and 139 mm Hg in the intervention and control groups, respectively. Also of interest were the effects of the intervention on proteinuria, costs, quality of life, self-management skills, and barriers and facilitators for implementation. There was no impact on proteinuria or the Partners in Health scale, but it showed promise for other parameters. The average cost per patient was $506 in the intervention group and $460 in the control group. There were big positive changes for quality-of-life measures. Median physical health summary score was higher for the intervention group than the control group at 3 months and persisted at 9 months. Median mental health summary score was similar between groups at baseline and 3 months, but at 9 months was higher in the intervention group than the control group. Focus groups with 21 individuals confirmed that participant success with interventions is affected by familial conditions, social factors, and community policies. For example, participants reported finding it difficult to determine the amount of sodium in restaurant meals. Participant responses also suggested they had a prestudy desire to change dietary behaviors. Collection of qualitative data is an often underappreciated exercise in clinical research and Humalda et al should be commended for gathering data that may influence intervention fidelity, especially in the longer term. It was disappointing to see that at 9 months, the intensive e-health lifestyle intervention was not superior to routine care, although it showed promise at 3 months. However, in light of the greater global public health goal of reducing excessive sodium consumption, it was promising to see that both study groups had reductions in urinary sodium excretion. The investigators suggest there was a “Hawthorne effect” in which awareness of being in a study may have motivated the control group to lower sodium intake more so than if they had not been in the study. There are other potential considerations as we try to understand these findings. First, the urinary sodium excretion findings raise the question as to what factors led to the lowering of sodium intake in the control group in the maintenance phase. Additional details about the information given to those in the control group would be helpful; that is, what is included in routine care? Is it possible that by making participants in the control arm aware of their serial 24-hour urine sodium results there was inadvertent contamination of the intervention in the control arm? There was also a long break between the third and fourth coaching sessions in the maintenance phase that may have contributed to relapse and the slightly increased sodium intake in the intervention group. It would be helpful to know what design factors prevented coaching sessions at weeks 24, 28, and 32. While this relatively small study may have lacked sufficient statistical power, the SUBLIME Study results are encouraging given that the major goal of dietary sodium reduction is to lower SBP and therefore slow the progression of CKD. However, they underscore the difficulties of implementing lifestyle interventions that can translate into long-term improvements in outcomes. The e-coaching intervention was developed with a multidisciplinary team and has all the elements of an efficacious lifestyle intervention, including goal setting, self-monitoring, motivational interviewing, relapse prevention, and timely feedback. However, as with previous behavioral interventions, this e-health intervention leaves us pondering how to promote healthy dietary patterns that are low in sodium and sustainable over the long term. Although current diet recommendations in CKD are based on data from the general population,11National Kidney FoundationK/DOQI clinical practice guidelines on hypertension and antihypertensive agents in chronic kidney disease.Am J Kidney Dis. 2004; 43: S1-S290PubMed Google Scholar,12Stevens P.E. Levin A. Kidney Disease: Improving Global Outcomes 2012 and clinical practice guideline.Ann Intern Med. 2013; 158: 825-830Crossref PubMed Scopus (1710) Google Scholar an emerging body of literature in individuals with CKD shows that healthy dietary patterns are associated with lower mortality13Kelly J.T. Palmer S.C. Wai S.N. et al.Healthy dietary patterns and risk of mortality and ESRD in CKD: a meta-analysis of cohort studies.Clin J Am Soc Nephrol. 2017; 12: 272-279Crossref PubMed Scopus (154) Google Scholar,14Gutiérrez O.M. Muntner P. Rizk D.V. et al.Dietary patterns and risk of death and progression to ESRD in individuals with CKD: a cohort study.Am J Kidney Dis. 2014; 64: 204-213Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar and lower risk for adverse renal outcomes.15Smyth A. Griffin M. Yusuf S. et al.Diet and major renal outcomes: a prospective cohort study. The NIH-AARP Diet and Health Study.J Ren Nutr. 2016; 26: 288-298Abstract Full Text Full Text PDF PubMed Scopus (59) Google Scholar The promotion of healthy diets is especially critical in this context in which hypertension, diabetes, and dyslipidemia are prevalent, and the global burden of CKD is not fully appreciated, with many individuals unaware of their impaired kidney function because there are no apparent early symptoms. Healthy diets have the collateral benefit of being lower in sodium. Across much of the world there is recognition that healthy dietary patterns are those that emphasize vegetables, fruits, and whole grains; include low-fat dairy products, poultry, fish, legumes, nontropical vegetable oils, and nuts; and limit intake of sodium, sweets, sugar-sweetened beverages, and red meats. In a population of patients with hypertension and CKD, a mean difference between the control and intervention groups of ~25 mmol/d (~570 mg/d) in sodium excretion and a concomitant decrease in BP is clinically meaningful. The quantitative and qualitative findings by Humalda et al remind us that long-term sustainable individual behavior change is difficult even with modern e-health approaches for self-management. Addressing individual behaviors is important and, as this study documented, so are the broader environmental factors that affect behaviors (eg, providing consumers with sodium content of restaurant foods). Continued work to address both individual and environmental factors will help make healthy food choices the default choice for patients with CKD. Cheryl A.M. Anderson, PhD, MPH, MS, C. Michael Wright, MD, DABCL, and Erica J. Ambeba, PhD. None. The authors declare that they have no relevant financial interests. Received December 24, 2019, in response to an invitation from the journal. Accepted December 26, 2019, after editorial review by an Associate Editor and a Deputy Editor. A Self-management Approach for Dietary Sodium Restriction in Patients With CKD: A Randomized Controlled TrialAmerican Journal of Kidney DiseasesVol. 75Issue 6PreviewPatients with chronic kidney disease (CKD) are particularly sensitive to dietary sodium. We evaluated a self-management approach for dietary sodium restriction in patients with CKD. Full-Text PDF