Nutritional status, hyperkalaemia and attainment of energy/protein intake targets in haemodialysis patients following plant-based diets: a longitudinal cohort study

Abstract

Background Patients undergoing haemodialysis (HD) are often discouraged from eating fruits and vegetables because of fears of hyperkalaemia and undernutrition, yet evidence to support these claims is scarce. We here explore the association between adherence to a healthy plant-based diet with serum potassium, surrogates of nutritional status and attainment of energy/protein intake targets in HD patients. Methods We performed an observational single-centre study of stable patients undergoing HD with repeated dietary assessment every 3 months. Patients were provided with personalized nutritional counselling according to current guidelines. The diet was evaluated by 3-day food records and characterized by a healthy plant-based diet score (HPDS), which scores positively the intake of plant foods and negatively animal foods and sugar. The malnutrition inflammation score (MIS) and serum potassium were also assessed at each visit. We used mixed-effects models to evaluate the association of the HPDS with markers of nutritional status, serum potassium levels and attainment of energy/protein intake targets. Results After applying inclusion and exclusion criteria, a total of 150 patients contributing to 470 trimestral observations were included. Their mean age was 42 years [standard deviation (SD) 18] and 59% were women. In multivariable models, a higher HPDS was not associated with serum potassium levels or odds of hyperkalaemia {potassium >5.5 mEq/L; odds ratio [OR] 1.00 [95% confidence interval (CI) 0.94–1.07] per HPDS unit higher}. Patients with a higher HPDS did not differ in terms of energy intake [OR for consuming <30 kcal/kg day 1.05 (95% CI 0.97–1.13)] but were at risk of low protein intake [OR for consuming <1.1 g of protein/kg/day 1.11 (95% CI 1.04–1.19)]. A higher HPDS was associated with a lower MIS, indicating better nutritional status. Conclusions In patients undergoing HD, adherence to a healthy plant-based diet was not associated with serum potassium, hyperkalaemia or differences in energy intake. Although these patients were less likely to reach daily protein intake targets, they appeared to associate with better nutritional status over time.

How to Overcome Anabolic Resistance in Dialysis-Treated Patients?

“…Plant proteins contribute to a large part of daily protein intake in the world population ( 135 ) and plant-based low protein diets are encountering increasing success for the prevention and treatment of several comorbidities associated with CKD ( 136 ). In addition, plant protein-based diets may correct many of the uremia-associated abnormalities ( 137 – 140 ). However, both in young and elderly subjects, plant proteins have a lower ability to increase MPS than animal proteins, when protein intake is low (≈0.8 g/kg/day) ( 17 , 141 ).…”

Fiber intake and health in people with chronic kidney disease

“…Supporting this, cross-sectional studies see weak or no correlations between serum potassium and dietary potassium in advanced CKD and dialysis [ 92 , 94–96 ]. Furthermore, cohort studies fail to identify a relationship between diets rich in fruits and vegetables and serum potassium levels [ 97 ]. Interestingly, the association of higher intake of fruits and vegetables tends to favor a lower mortality risk in patients on maintenance HD [ 102 ].…”

“…All these nutrients (glucose, fructose, alkali and fiber) are present in fruits and vegetables and overall add support for the notion that a plant-based diet may not be unsafe for people with CKD. We speculate that by restricting fruits and vegetables we may be facilitating rather than preventing potassium absorption [ 96 , 97 , 102 ]. Finally, the bio-availability of potassium in form of unprocessed and fresh fruits and vegetables may be lower than that from potassium coming from protein foods and processed plant foods (e.g.…”

A Mini Review of Plant-Based Diets in Hemodialysis

“…In another study by Wu et al [25], potassium levels among vegetarian hemodialysis patients (5.0 mg/dL ±0.2) and nonvegetarian hemodialysis patients (4.8 mg/dL ±0.12) were not significantly different. Gonzalez-Ortiz et al [31] also conducted a prospective study ( n = 150) on patients undergoing hemodialysis and found that a higher healthy plant-based diet score was not associated with the odds of hyperkalemia (potassium >5.5 mEq/L; OR 1.00; 95% CI: 0.94–1.07).…”

“…As such, hyperkalemia remains a concern in the management of any patient on hemodialysis, regardless of their dietary choices. Nonetheless, studies on patients undergoing hemodialysis while eating plant-based diets have not shown increased risks of hyperkalemia [2, 25, 29, 31]. More prospective studies need to be conducted to draw more definitive conclusions on hyperkalemia and plant-based diets in hemodialysis.…”