Original ResearchCan Renal Nutrition Education Improve Adherence to a Low-Protein Diet in Patients With Stages 3 to 5 Chronic Kidney Disease?
Introduction
Protein restriction is traditionally recommended for patients with chronic kidney disease (CKD) who are not yet receiving dialysis. For adults with CKD who do not have diabetes and are not receiving dialysis (CKD stages 3-5), a protein-controlled diet providing 0.6 to 0.8 g dietary protein per kg body weight per day should be prescribed, as previously described.1, 2 The benefits of lowering the protein intake to ameliorate the metabolic disturbances that arise as a consequence of loss of renal function include better control of serum bicarbonate, phosphorus, urea nitrogen, and cholesterol levels,3, 4 as well as improved insulin sensitivity and a reduction in proteinuria.5, 6, 7, 8, 9 The low-protein diet is nutritionally safe10 and capable of improving nutritional status.8, 11
An important pitfall in restricting dietary protein is low adherence. Some studies report that only 20% to 46% of patients are able to successfully adhere to a diet with 0.6 to 0.8 g of protein/kg/day.6, 11, 12 The reasons for this finding are diverse and include social and economic factors (i.e., poverty, low educational level), treatment-related factors (i.e., lack of a renal dietitian and short consultations without follow up at predialysis care), and patient-related factors (i.e., limited knowledge of the reasons behind this dietary approach and of the food sources that are rich in protein; dietary dissatisfaction and lack of self-perception of success).12, 13 It is therefore relevant to work on comprehensive nutritional strategies that enable a level of adherence acceptable for the patient and capable of yielding the benefits of lowering protein intake.12 These strategies include the prescription of dietary plans as well as the development of educational material and behavioral changes compatible with the patient's social and cultural environment.
Studies focusing on educational strategies in patients with CKD have to date been focused on the control of fluid status and phosphorus intake in patients undergoing dialysis.14, 15 Strategies used in these studies included the use of education materials (lectures, folders, posters, handouts, puzzles, and games), as well as more practical actions such as visits to restaurants, development of cooking recipes, and motivational interviewing.14, 15, 16, 17 These studies showed improved adherence to these complex dietary regimens.
To the best of our knowledge, no study to date has evaluated the impact of education programs in reducing protein intake and improving adherence to a low-protein diet in patients with CKD who are not yet receiving dialysis. Campbell et al.10 reported that individualized nutrition counseling had a positive effect on overall nutritional status in conservatively treated patients, but the adherence to this regimen was not assessed. Therefore, in this study we hypothesized that a specifically designed nutrition education program would contribute to decreased protein intake and would improve adherence in patients with CKD who are not yet receiving dialysis over and above our standard dietary counseling.
Section snippets
Methods
This was a randomized controlled clinical trial lasting 5 ± 1.5 months (4-7 months). The local research ethical committee approved this project, and all patients provided written informed consent before their inclusion in the study. The study was conducted at the CKD outpatient clinic at Pedro Ernesto University Hospital, Rio de Janeiro, Brazil. The following enrollment criteria were applied: adult (age ≥18 years), estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, absence of
Results
Table 1 shows no significant differences at baseline between the 2 nutrition intervention groups regarding demographics and clinical characteristics. Regarding marital status, most subjects in both groups were married. The majority of patients were considered to have CKD stages 3 to 4, and hypertension was the main comorbidity observed.
Table 2 describes changes in anthropometric parameters during the study according to the 2 intervention groups. Our population was composed by a majority of
Discussion
This randomized interventional study shows that a specifically designed nutrition education program aimed at reducing protein intake was effective in patients with CKD stages 3 to 5 compared with standard dietary counseling. This study emphasizes the usefulness of dedicated education strategies to achieve patient adherence to dietary restrictions in CKD.
Since monthly visits to the outpatient clinic are not feasible in the long run in routine clinical care, educational strategies such as the one
Practical Application
Because low adherence to the protein-restricted diet remains 1 of the biggest challenges when advising patients regarding the low-protein diet, the results and conclusion presented in this study will encourage and guide renal dietitians to plan the intervention of a low-protein diet.
Acknowledgments
To Eliete Coutinho Rodrigues, the technician of the laboratory of Pedro Ernesto University, for her important contribution in all laboratory analyses performed in this study. To Anete Mecenas for her participation in the study.
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Funding Support: J.J.C. acknowledges grant support from the Swedish Medical Research Council. The other authors declare that they have no relevant financial interests.