Diet in Chronic Kidney Disease: an integrated approach to nutritional therapy

Associations between diet quality, demographics, health conditions and spice and herb intake of adults with chronic kidney disease

Scant literature has been able to demonstrate an association between dietary habits and spice and herb consumption, especially for those who have chronic kidney disease. The objectives of this study were to 1) determine the frequency and quantity of spices and herbs consumed and 2) determine the associations between diet quality and its food components, demographics, and health conditions with spice and herb frequency and variety consumption of adults with chronic kidney disease. A cross-sectional online study was conducted with adults with various stages of chronic kidney disease (n = 71). Participants responded to an online demographic, diet and spice and herb questionnaire on RedCap. Diet quality was determined through the diet questionnaire. Descriptives, frequencies and Spearman correlations were conducted using SPSS v28 with a significance of p<0.05. Most participants were in chronic kidney disease stage 3 (42.3%) with a majority (98.6%) self-identifying as non-Hispanic white. On average, participants consumed black pepper more than once daily (47.9%) with the spice quantity at 5 g. The median diet quality score was 38.5 (range 31.5-48.5). Positive associations were identified with overall diet quality scores and certain spices such as basil (r = 0.33; p<0.01) and cinnamon (r = 0.37; p<0.002). Further associations were seen with food groups, self-identifying as white and health conditions with spice frequency and variety of spices and herbs consumed. Overall, positive associations were observed with diet quality and spice and herb intake, in which higher diet quality scores would indicate higher consumption of spices and herbs. Further research should focus on diet quality and spice and herb consumption in reducing progression of this disease.

Quality characteristics and sensory evaluation of protein-rich baked snacks for adults with chronic kidney disease: a proof of concept study

BACKGROUND

Adults with chronic kidney disease (CKD) have different protein requirements than the general population. Limited protein-rich baked snack options are available for CKD adults. The purpose of this proof of concept study was to develop two protein-rich baked snacks made with whey protein isolate and soy protein isolate and to evaluate their quality characteristics and sensory perceptions for adults with CKD.

METHODS

A control formulation was obtained from the American Association of Cereal Chemists to develop three formulations-dried milk (control), whey protein isolate and soy protein isolate at an unbaked weight of 30 g. Product quality characteristics included moisture content, water activity, shape and size, and texture profile. For the sensory perception, healthy adults (n = 101) and adults with CKD (n = 57) completed a 9-point hedonic scale for appearance, flavor, texture, and overall acceptability.

RESULTS

Protein content for the whey protein isolate and soy protein isolate reached 20% total weight. Despite containing similar moisture, both formulations were harder than the control (p < 0.001). Healthy participants preferred the whey protein isolate-based snack over the soy protein isolate-based snack for all attributes (p < 0.05). Differences in the same attributes were not perceived among CKD participants (p > 0.05). Open-ended responses from both healthy and CKD participants indicated that the soy protein isolate formulation was softer and sweeter compared to the whey protein isolate formulation.

CONCLUSION

Overall, adults with CKD preferred both the whey protein isolate-and soy protein isolate-formulated snacks. These protein-rich baked snacks can be further modified to serve as an alternative snack choice for adults with CKD and used in future clinical trials.

Association of carbohydrate intake from different sources with all-cause and cardiovascular mortality among chronic kidney disease populations: assessment of 1999-2018 National Health and Nutrition Examination Survey participation

This study analysed the data from the NHANES (1999-2018) to examine how different sources of carbohydrate intake affected the all-cause and cardiovascular mortality of 11,302 chronic kidney disease (CKD) patients. The data were adjusted for other factors using various methods. The results showed that CKD patients (stages 1-2 and 3-5) who consumed more carbohydrates from whole grains, fruits, vegetables and less carbohydrates from fruit juice or sauces had lower mortality rates. Replacing fat intake with carbohydrates from whole grains (HR = 0.86[0.78-0.95]), fruits (raw) (HR = 0.79[0.70-0.88]) and non-starchy vegetables (HR = 0.82[0.70-0.96]), but not protein intake, was linked to lower all-cause mortality. The fibre content in carbohydrates might partly account for the benefits of selected carbohydrate intake. This study provided practical recommendations for optimising the carbohydrate sources in CKD patients.

Barriers to and Strategies for Dietary Adherence: A Qualitative Study Among Hemodialysis/Peritoneal Dialysis Patients and Health Care Providers

OBJECTIVES

The objectives of this study were: (1) investigate hemodialysis (HD)/peritoneal dialysis (PD) patients' barriers to dietary adherence, (2) identify strategies to overcome these barriers, and (3) examine dialysis providers' perceptions toward patients' barriers to dietary adherence and strategies to overcome these barriers.

METHODS

A qualitative descriptive approach was conducted from February-May 2022. A total of 21 HD/PD participants and 11 health care providers participated in individual interviews. HD/PD participants also responded to a 57-item food frequency questionnaire. Six months of serum laboratory values were obtained from the medical charts. Content analysis methodology was used to identify themes. Mann-Whitney U tests were conducted to examine diet quality and laboratory values of the HD and PD participants using SPSS v.27 with statistical significance of P < .05.

RESULTS

The median (interquartile range) diet quality score for HD/PD patients was 36 (26-43) with no differences observed between the patient populations. Mann-Whitney U tests showed no differences between serum laboratory values between the patient populations. Barriers identified by the HD/PD patients were communication/patient education and dietary habits. Barriers identified by the health care providers were communication/patient education and socioeconomic status. Strategies to overcome these barriers were enhancing communication between all parties involved in the care and tailoring educational information to the patient's background.

CONCLUSIONS

Communication and patient education were themes identified among both health care providers and patients. Therefore, open communication among the patients and providers and enhancement of the nutrition education handouts may improve dietary adherence.

The effect of egg white diet on phosphorus control in dialysis patients

INTRODUCTION

Nutritional interventions have been envisaged to improve hyperphosphatemia and malnutrition, two important risk factors associated with mortality in dialysis patients. We evaluated the effects of egg white consumption on serum phosphate and malnutrition in dialysis patients.

METHODS

In an open-label, per protocol clinical trial, conducted in Kerman dialysis centers, 150 hemodialysis patients aged ≥18 years with serum phosphorus ≥5.5 mg/dl were included in the study. All participants limited their intake of foods containing phosphorus for 4 weeks, and then they were divided into a control and an intervention group. The control group continued their ordinary diet and the participants in the intervention group consumed a Telavang egg white pack (containing six egg whites, 96 calories, 24 g protein) as a substitute for meat products 3 days a week for 8 weeks. Finally, changes in serum albumin, phosphorus, calcium, PTH, and cholesterol were measured.

FINDINGS

At the baseline, there were no significant differences in the laboratory variables between the two groups. After 8 weeks, serum cholesterol (124.3 ± 38.1, vs. 135.8 ± 28.8, p = 0.003) and phosphorus levels (4.5 ± 1.03, vs. 6.7 ± 1.5, p = 0.001) were significantly lower in the intervention group compared with the control group. Also, serum albumin (4.5 ± 0.07 vs. 3.7 ± 0.4, p = 0.001) was significantly higher in the intervention group. Moreover, phosphorus, PTH, and cholesterol levels in the intervention group were significantly lower than their baseline values (p = 0.001).

CONCLUSION

The results showed that the egg white could be a useful source of protein for dialysis patients, as it simultaneously reduces serum phosphorus and cholesterol, and increases serum albumin.

The Preventive Effects of Fermented and Germinated Foxtail Millet Whole Grain on Kidney Damage in a Diabetic Mouse Model

Diabetic kidney disease (DKD) is an important complication of diabetes. The prevention of DKD can effectively reduce the mortality rate of diabetic patients and improve their quality of life. The present study examined the effects of fermented and germinated foxtail millet whole grain (FG-FM) on kidney lesions in a diabetic mouse model (Db/Db mice). The results proved that the FG-FM consumption significantly alleviated the kidney tissue damage in the diabetic mouse model. The transcriptome analysis of kidney tissues demonstrated that the overactivation of signaling pathways related to inflammation and immunity in the diabetic mouse model was significantly inhibited with the FG-FM intake. Moreover, the consumption of the FG-FM diet effectively elevated the bacterial diversity, increased the relative abundance of probiotics and decreased the relative abundance of previously reported DKD-related bacteria in the gut microbiota of diabetic mice. Our study confirmed foxtail millet as a potential source of functional food for the non-pharmacological intervention of DKD.

Effects of Nutritional Knowledge of Informal Caregivers on Depression and Metabolic Outcomes of Hemodialysis Patients

Chronic renal failure (CRF) makes significant changes in the life of patients and their families. A good family support has a positive effect on successful patients' adaptation to the treatment and compliance with dietary regimen. This study aimed to examine the effects of nutritional knowledge of informal caregivers on depression and metabolic outcomes of hemodialysis patients. This was a cross-sectional study conducted at Baskent University Hemodialysis Center with 116 hemodialysis patients and their informal caregivers. Findings revealed that the caregivers who were the couple of the patients had the highest nutritional knowledge level than the other caregivers (p < .05). The postgraduate caregivers were more likely to have high nutritional knowledge level than the others (p < .05). The inflammation marker of the patients was significantly lower in the group of caregivers with higher level (T3 group) of nutritional knowledge than the others (p < .05). The mean CES-D scores were also more likely to be low in T3 group than in the others (p < .05). These findings highlight that the nutritional knowledge of caregivers of hemodialysis patients may have an additional benefit on patients' nutritional management and metabolic outcomes.

Effect of self-care intervention for controlling interdialytic weight gain among patients on haemodialysis: A systematic review and meta-analysis

AIMS AND OBJECTIVES

This study aims to identify the combined effects of self-care or self-management nursing interventions on primary (interdialytic weight gain) and secondary (potassium, phosphorous, self-care and self-efficacy) outcomes in haemodialysis patients with chronic kidney disease.

BACKGROUND

Prior systematic reviews and meta-analyses revealed inconclusive evidence regarding the effects of self-care or self-management nursing interventions among the patients on haemodialysis. Also, insufficient or unclear descriptions of methods resulted in weak empirical evidence of such effects.

DESIGN

Systematic review and meta-analysis were used.

METHODS

Four databases were searched to identify 36 articles published from 2000 to 2020. Keywords were selected according to the Population Intervention Comparison Outcome format using MeSH terms and text words. The meta-analysis involved synthesis of effect size, tests of homogeneity and heterogeneity, and funnel plot, Egger's regression test, and Begg's test for assessing publication bias. This study was performed based on the Guidelines of Systematic Reporting of Examination presented in the PRISMA checklist (Appendix S1) and the Cochrane Handbook for Systematic Reviews of Interventions. The search protocol has been registered at the PROSPERO International Prospective Register of Systematic Reviews.

RESULTS

The overall effect on interdialytic weight gain was -0.26, suggesting a small effect size, with the interdialytic weight gain after nursing interventions decreasing significantly. Among the type of nursing interventions, the overall effect on interdialytic weight gain of education programmes and fluid and sodium control programmes was -0.36 and 0.25, respectively, a small effect size, and was statistically significant.

CONCLUSIONS

Based on the results of this study, healthcare professionals may encourage the patients on haemodialysis to engage in self-directed management of their symptoms, such as health contract, and promote health literacy through improving their self-efficacy.

RELEVANCE TO CLINICAL PRACTICE

This meta-analysis could provide fundamental data to assist with the development of an evidence-based practice guideline.

Usefulness of Extra Virgin Olive Oil Minor Polar Compounds in the Management of Chronic Kidney Disease Patients

Chronic kidney disease (CKD) is one of the most common chronic non-communicable degenerative diseases and it represents an important risk factor for cardiovascular morbidity and mortality. The Mediterranean diet, in which extra virgin olive oil (EVOO) is the main source of vegetal fats, represents a nutritional-diet regimen that is useful for the treatment of CKD and its comorbidities. We tested two different EVOOs, characterized by a high (Synergy) and medium (Luxolio) content of minor polar compounds (MPCs), detected by HPLC-DAD-MS analysis, in 40 nephropathic patients, at a dose of 40 mL/day for 9 weeks. We evaluated the effects of these two EVOOs on renal function, body composition, oxidative stress, and inflammatory state, after 9 weeks of EVOOs consumption (T1) and after 2 months of wash-out (T2). We observed an improvement of renal function biomarkers (estimated-glomerular filtration rate, albuminuria, azotemia, uric acid), lipid profile, oxidative stress, inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein) and in body composition at T1. These healthy effects were greater and persisted over time after the wash-out period in Synergy patients. The high MPC EVOO content seems to exert an antioxidant and anti-inflammatory effect in nephropathic patients and these protective actions are maintained over time.

Development of the Adherence to Healthy Behaviors Scale

Adherence to healthy behaviors is a protective factor in the disease progression of chronic kidney disease (CKD). Measuring adherence can lead to the recognition of unhealthy behaviors and the suggestion of programs to prevent poor health outcomes. An assessment measurement for patients with CKD not requiring dialysis was developed and psychometrically tested. A convenience sample (n = 330) of patients with CKD attending a nephrology clinic in southern Taiwan completed the 13-item Adherence to Healthy Behaviors Scale (AHBS). A principal axis factor analysis and a parallel analysis demonstrated a three-factor structure accounting for 47.16% of the total variance. Confirmatory factor analysis indicated a good model fit. The criterion-related validity was adequate (r = .51; p < .000), with a Cronbach's alpha of .70; the test-retest reliability demonstrated good stability (r = .70; p < .000). The AHBS is a valid, reliable instrument to assess adherence to healthy behaviors among patients with CKD.

Nutritional management in patients with chronic kidney disease

The global prevalence of chronic kidney disease (CKD) is increasing with the aging of populations worldwide. As kidney function declines, the accumulation of metabolic waste products and excessive electrolytes can significantly impair the health of patients with CKD. As nutritional management of patients with CKD is thought to control uremic symptoms and provide beneficial effects on the progression of kidney dysfunction, the diet of patients with CKD should be an important consideration in their care. Many guidelines recommend limiting protein intake in these patients, as high-protein diets aggravate kidney dysfunction. Excess sodium may be associated with CKD progression and all-cause mortality and, therefore, limiting salt intake is generally recommended. Low potassium is associated with muscle weakness and hypertension, whereas high potassium is associated with cardiac arrhythmia. Therefore, recent guidelines recommend adjusting dietary potassium intake on an individual basis to maintain serum potassium levels within the normal range. Appropriate dietary calcium intake is recommended to maintain calcium balance in patients with CKD G3, G4. Given the many dietary considerations for patients with CKD, effective nutritional management is challenging. Individualized strategies are needed to ensure the best outcome for patients with CKD.