Nutritional and Hydration Status and Adherence to Dietary Recommendations in Dalmatian Dialysis Patients

Protein-energy wasting (PEW) is considered one of the major complications of chronic kidney disease (CKD), particularly in dialysis patients. Insufficient energy and protein intake, together with clinical complications, may contribute to the onset and severity of PEW. Therefore, the aim of the study was to analyze the differences in nutritional and hydration status and dietary intake among Dalmatian dialysis patients. Fifty-five hemodialysis (HD) and twenty peritoneal dialysis (PD) participants were included. For each study participant, data about body composition, anthropometric, laboratory, and clinical parameters were obtained. The Malnutrition Inflammation Score (MIS) and two separate 24-h dietary recalls were used to assess nutritional status and dietary intake. The Nutrient Adequacy Ratio (NAR) and Mean Adequacy Ratio (MAR) were calculated to compare actual dietary intake with recommended intake. Additionally, the estimated 10-year survival was calculated using the Charlson Comorbidity Index. The prevalence of malnutrition according to MIS was 47.3% in HD and 45% in PD participants. Significant differences in fat tissue parameters were found between HD and PD participants, whereas significant differences in hydration status and muscle mass parameters were not found. A significant difference in NAR between HD and PD participants was noticed for potassium and phosphorus intake, but not for MAR. MIS correlated negatively with anthropometric parameters, fat mass, visceral fat level and trunk fat mass, and iron and uric acid in HD participants, whereas no significant correlations were found in PD participants. The estimated 10-year survival correlated with several parameters of nutritional status in HD and PD participants, as well as nutrient intake in HD participants. These results indicate a high prevalence of malnutrition and inadequate dietary intake in the Dalmatian dialysis population which, furthermore, highlights the urgent need for individualized and structural nutritional support.

The effect of dietary phosphorus load and food matrix on postprandial serum phosphate in hemodialysis patients: a pilot study

Background: Potential dietary strategies for controlling hyperphosphataemia include the use of protein sources with lower phosphorus bioavailability such as pulses and nuts, focus on phosphorus to protein ratios and the avoidance of all phosphate additives. Methods: We conducted a controlled crossover feeding study in 8 haemodialysis (HD) patients to investigate the acute postprandial effect of a modified versus standard low phosphorus diet for one day on serum phosphate, potassium and intact parathyroid levels in prevalent HD patients. Each participant consumed the modified diet on one day and the standard diet on a second day one week apart. The modified diet included beef and less dairy, with a lower phosphorus to protein ratio, as well as plant-based protein, whole grains, pulses and nuts containing phytates which reduces phosphorus bioavailability. Both diets were tailored for each participant to provide 1.1g protein/kg ideal body weight. Participants provided fasting bloods before breakfast, a pre-prandial sample before the lunch time main meal and samples at one-hour intervals for the four hours after the lunch time main meal, for analysis of phosphate, potassium and intact parathyroid hormone (iPTH). Results: At four hours post the lunch time main meal on each study day, individuals on the modified diet had serum phosphate readings 0.30 mmol/l lower than when on the standard diet (p-value = 0.015, 95% confidence interval [CI] -0.57, -0.04). The corresponding change in serum potassium at four hours was a decrease of 0.675 mmol/l (p-value = 0.011, CI -1.25, -0.10). Conclusions: Decreases in both serum phosphate and serum potassium readings on a modified low phosphorus diet encourage further larger studies to explore the possibility of greater food choice and healthier plant-based diets in HD patients.  ClinicalTrials.gov registration: NCT04845724 (15/04/2021).

Which Method Should Be Used to Assess Protein Intake in Peritoneal Dialysis Patients? Assessment of Agreement Between Protein Equivalent of Total Nitrogen Appearance and 24-Hour Dietary Recall

OBJECTIVES

After dialysis initiation, a high protein diet is recommended due to significant nutrient losses through dialysate and increased risk of protein energy wasting. In peritoneal dialysis (PD) patients, protein intake can be assessed through different methods that have some advantages and limitations, which affect its use on routine care. The aim of this study is to evaluate the agreement between 2 different methods (24-hour dietary recall and PNA-protein equivalent of total nitrogen appearance) on estimating protein intake in PD patients.

DESIGN AND METHODS

Patients on PD for at least 3 months, aged 18 years old or more, were enrolled. To estimate protein intake, 24-hour dietary recall and PNA was used. PNA was calculated from 24-hour urine on the same day of the 24-hour dietary recall.

RESULTS

Fifty individuals on PD were included, mean age 55.7 ± 16.2 years, and body mass index 26.0 ± 4.5 kg/m². The average energy consumption was 1788.79 ± 504.40 kcal/day, which corresponds to 26.81 ± 9.11 kcal/kg current body weight (BW)/day and 29.82 ± 8.39 kcal/kg ideal body weight (IBW)/day. The median of total daily and normalized protein intake estimated using dietary recall was 61.43 (45.28-87.40) g/day, 0.90 (0.58-1.22) g/kg current BW/day, and 1.04 (0.77-1.32) g/kg IBW/day, respectively. Daily protein intake estimated by PNA was 55.75 (48.27-67.74) g/day, protein intake normalized by current BW was 0.81 (0.72-0.99) g/kg and 0.92 (0.83-1.06) g/kg IBW/day. Bland-Altman analysis indicates no systematic bias for the assessment of total protein intake and normalized protein intake for current and ideal BW. Significant proportionality bias was observed for both evaluations, showing there is a dispersion of the values.

CONCLUSIONS

Despite the absence of systematic bias in the Bland-Altman analysis, there is no agreement in the assessment of protein intake by dietary recall and PNA, due to the existence of proportionality bias. Thus, values can be influenced biased by the magnitude of the measures.

Intradialytic Nutrition and Hemodialysis Prescriptions: A Personalized Stepwise Approach

Dialysis and nutrition are two sides of the same coin—dialysis depurates metabolic waste that is typically produced by food intake. Hence, dietetic restrictions are commonly imposed in order to limit potassium and phosphate and avoid fluid overload. Conversely, malnutrition is a major challenge and, albeit to differing degrees, all nutritional markers are associated with survival. Dialysis-related malnutrition has a multifactorial origin related to uremic syndrome and comorbidities but also to dialysis treatment. Both an insufficient dialysis dose and excessive removal are contributing factors. It is thus not surprising that dialysis alone, without proper nutritional management, often fails to be effective in combatting malnutrition. While composite indexes can be used to identify patients with poor prognosis, none is fully satisfactory, and the definitions of malnutrition and protein energy wasting are still controversial. Furthermore, most nutritional markers and interventions were assessed in hemodialysis patients, while hemodiafiltration and peritoneal dialysis have been less extensively studied. The significant loss of albumin in these two dialysis modalities makes it extremely difficult to interpret common markers and scores. Despite these problems, hemodialysis sessions represent a valuable opportunity to monitor nutritional status and prescribe nutritional interventions, and several approaches have been tried. In this concept paper, we review the current evidence on intradialytic nutrition and propose an algorithm for adapting nutritional interventions to individual patients.

Safety and Efficacy of Using Nuts to Improve Bowel Health in Hemodialysis Patients

OBJECTIVE

Constipation is common in patients with end-stage kidney disease. Nondrug strategies to manage constipation are challenging because of dietary potassium, phosphate, and fluid restrictions. Nuts are a high-fiber food but are excluded from the diet because of the high potassium and phosphate content. The aim of this study was to examine the safety and efficacy of using nuts to improve constipation in adults undertaking hemodialysis (HD).

DESIGN AND METHODS

Adult patients undertaking HD were recruited to this nonrandomized, 10-week repeated measures, within-subject, pragmatic clinical trial, conducted in two HD units. The intervention consisted of consumption of 40g of raw almonds daily for four weeks, followed by a two-week washout and four-week control period. The primary safety outcome measures were change in predialysis serum potassium and phosphate levels. The primary efficacy outcome was reduction in constipation, measured using the Bristol Stool Form Scale and Palliative Care Outcome Scale (POS-S) renal symptom score. Secondary outcomes included quality of life, selected uremic toxins, cognition, gut microbiota profile, and symptom burden.

RESULTS

Twenty patients completed the trial (median age: 67 [interquartile range: 57.5-77.8] years, 51% male). After controlling for dialysis adequacy, anuria, dietary intake, bicarbonate, and parathyroid hormone, there were no statistically significant changes in serum potassium (P = 0.21) or phosphate (P = 0.16) associated with daily consumption of almonds. However, statistically significant improvements in constipation were seen at weeks 2, 3, 4, and 10. There were statistically significant improvements in quality of life (P = 0.030), overall symptom burden (P = 0.002), vomiting (P = 0.020), itching (P = 0.006), and skin changes (P = 0.002).

CONCLUSION

Daily consumption of almonds for four weeks was safe, effective, and well tolerated. Improvements in quality of life and symptom burden warrant further research to elucidate potential mechanisms. The findings support the potential reinclusion of foods such as nuts into the diet of patients who underwent HD.