Pisa, Italy: Study on Plant-Based Diets for CKD Patients

Chronic kidney disease (CKD) patients often experience a frequent complication of hyperkalemia (HK). Vegetable-based renal diets are considered risky for such patients due to the high content of potassium (K). However, a recent study has found plant-based low-protein diets to be safe for CKD patients.

According to the study, published in the journal Internal and Emergency Medicine, plant-based low-protein diets are not associated with a significantly higher prevalence of HK.

Claudia D'Alessandro, University of Pisa, Pisa, Italy, and colleagues described the correlation and prevalence of chronic HK in CKD patients on nutritional care, particularly the risk of HK in patients on plant-based versus animal-based low-protein diets (LPD).

The study recruited adult CKD patients not on dialysis, attending a renal nutrition clinic from November 2014 to May 2019. The researchers evaluated a total of 870 accesses in 219 patients (172 males, 47 females, age 67 ± 13 years). HK was defined as mild when K serum level was 5.1–5.9 mEq/l, moderate when K serum level was 6.0–6.9 mEq/l, and severe HK when K serum level was ≥ 7 mEq/l. Biochemical, anthropometric data, and medications were recorded.

Key Findings of the Study

• The prevalence of HK in all the renal nutrition visits was 26.1%; all but six cases were mild HK, whereas no severe HK was observed.
• The prevalence of HK was associated with decreased eGFR, up to 36.5% for eGFR < 20 ml/min. Medications were similar in hyperkalemic and normokalemic patients, RAASi being present in up to 85% of patients.
• In a follow-up of 40 ± 14 months, no association was found between HK and mortality, whereas HK, at the start of follow-up, showed a trend to increased ESRD risk.
• Serum potassium levels and prevalence of HK were not different between patients on animal-based low-protein diet and plant-based low-protein diet.
• Chronic HK is quite prevalent in a renal nutrition clinic, especially when eGFR falls below 60 ml/min, reaching the highest prevalence in CKD stage 4.
• Hyperkalemia is mostly mild, with moderate to severe HK being quite infrequent.
• Hyperkalemia was not associated with a higher risk of mortality, whereas a trend, although not statistically significant, was observed for lower ESRD-free survival.

"Plant-based low-protein diet is not associated with a significantly higher prevalence of HK with respect to animal-based LPD at the same residual kidney function," concluded the authors.

The study, "Prevalence and correlates of hyperkalemia in a renal nutrition clinic," is published in the journal Internal and Emergency Medicine.

DOI: https://doi.org/10.1007/s11739-020-02353-9