A Whole Food Plant-Based Diet With a Novel Potassium-Binding Resin in a Patient With Advanced Chronic Kidney Disease

Abstract

Chronic kidney disease (CKD) is a major health problem with substantial morbidity and mortality. Plant-based diets decrease the incidence of CKD and progression of kidney disease and help prevent and treat the important comorbidities of obesity, type 2 diabetes, hypertension, and cardiovascular disease. However, in patients with CKD, there is concern that a plant-based diet may contribute to life-threatening hyperkalemia. We present a patient with CKD secondary to hypertensive glomerulosclerosis that worsened despite standard of care treatment. Shared decision making was used to initiate a whole food plant-based diet along with a potassium-binding resin (Patiromer) to control the potassium levels. The patient was able to be maintained on the whole food plant-based diet and an angiotensin-converting enzyme inhibitor without the development of hyperkalemia. This case shows that patients with CKD may be able to enjoy the benefits of a whole food plant-based diet while decreasing the risk of hyperkalemia by using the new potassium binders.

The US Department of Agriculture dietary guidelines recommend plant-rich diets such as the Dietary Approaches to Stop Hypertension (DASH).

Chronic kidney disease (CKD) is a major public health problem affecting more than 10% of the US population. It is associated with substantial mortality and morbidity, including cardiovascular disease and progression to end-stage renal disease (ESRD). ¹ The US Department of Agriculture dietary guidelines recommend plant-rich diets such as the Dietary Approaches to Stop Hypertension (DASH). It is rich in whole grains, fruits, vegetables, and low-fat dairy products limiting saturated fat and processed meats and provides plenty of fiber, potassium, phosphorus, magnesium, and calcium. ² Research has shown that plant-based diets are associated with low risk of obesity, type 2 diabetes mellitus, hypertension, cardiovascular disease, and delay in the progression of kidney disease.^2,3 There is concern among nephrologists in prescribing such diets to patients with advanced CKD due, in part, to concerns over their high potassium content and the risk for hyperkalemia,^4,5 depriving these patients of many heart-healthy foods. ⁶

Recently 2 new oral potassium binding agents, sodium zirconium cyclosilicate (SZC) and Patiromer, have been Food and Drug Administration approved for the treatment of hyperkalemia. ⁷ Thus far, studies of SZC and Patiromer do not systematically control for diet leading to inconclusive data. ⁶ We report a case of a patient with advanced CKD and hyperkalemia who was able to gain the advantages of a whole-food plant-based diet while safely controlling the serum potassium with the use of an oral potassium-binding agent.

Case

The patient is a 68-year-old male who presented to the nephrology outpatient office for evaluation of elevated creatinine and nephrotic range proteinuria. His weight at presentation was 218 pounds with a body mass index of 29.6 kg/m²; his systolic blood pressure before presentation had been ranging between 140 and 160 mm Hg for which he was taking lisinopril 10 mg daily. The initial creatinine level was 2.26 mg/dL. A urinalysis dipstick was negative for blood but showed 2+ protein. Urine microscopic exam showed 2 rbc/hpf and 0 wbc/hpf. The spot urine protein to creatinine ratio was 5.16. A serological evaluation included normal C3 and C4 levels, negative ANA (antinuclear antibody), negative hepatitis B, negative serum immunofixation, negative cANCA and pANCA (ANCA = antineutrophil cytoplasmic antibody).

One week later, the patient underwent a percutaneous renal biopsy. The pathology results showed features supporting severe arterial nephrosclerosis, focal segmental glomerulosclerosis, and moderate to severe arteriosclerosis and arteriolosclerosis. These findings support a diagnosis of hypertensive nephrosclerosis. The immunofluorescence findings did not support any immune complex mediated process or paraprotein associated renal disease. The pathologist commented that if the biopsy was representative of the kidney in general, the findings represented near end-stage renal disease.

A treatment plan including tight blood pressure control, use of angiotensin-converting enzyme (ACE) inhibitor, lipid control, and dietary salt restriction was instituted. Despite this treatment plan, his creatinine increased to 3.23. His potassium level was running in the upper range of normal to mildly elevated.

The patient was initially on a standard American diet; hence, the benefits of a whole food plant-based diet were discussed with the patient, along with the risk of hyperkalemia. A shared decision was made to transition to a whole food plant-based diet with the addition of an oral potassium-binding resin to prevent hyperkalemia, Patiromer 8.4 g orally daily. The patient was provided with initial in-office counseling on the nature and benefits of a whole food plant-based diet. Over the course of his follow-up, the patient was provided with websites, cookbook titles, and free meal planning apps to facilitate his transition to a whole food plant-based diet. He was provided counseling and encouragement on this lifestyle at every subsequent follow-up visit approximately every 3 months.

The patient was followed for 18 months after the initiation of the whole food plant-based diet. He was able to continue taking his ACE inhibitor at a reduced dose (lisinopril 5 mg daily) for continued renal protection along with blood pressure control. The patient’s most recent creatinine was 2.98 mg/dL with a glomerular filtration rate (GFR) of 25 mL/min/1.73 m², which compares favorably to a creatinine of 2.97 when the whole food plant-based diet was started. After the follow-up period his potassium remained stable; his most recent one was 5.4 mEq/L compared to 5.8 mEq/L initially. There were no episodes of severe hyperkalemia or associated hospitalizations since initiation of the whole food plant-based diet. The patient’s lipid panel remained within normal range; the most recent results were total cholesterol, 179; low-density lipoprotein, 101; high-density lipoprotein, 63; triglycerides, 75, maintained on Pravastatin 20 mg at a stable dose. The patient’s blood glucose remained continuously in a nondiabetic range and his body mass index remained unchanged.

Discussion

In patients with CKD, the risk of cardiovascular disease and all-cause mortality is often higher than the risk for progression to ESRD and it depends on the level of kidney function, proteinuria, and age.^1,8 The treatment goals should include kidney protection and cardiovascular risk reduction with glycemic control, hypertension management and inhibition of the renin angiotensin aldosterone system.^9-11 Clinicians should also counsel about smoking cessation, regular exercise, limiting alcohol intake, keeping body mass index within the normal range, and a diet high in fruit, vegetables, and whole grains, ¹² avoidance of nephrotoxic agents such as NSAIDs, and salt restriction. ¹³

There is growing evidence that plant based diets delay progression to ESRD and dialysis and may improve survival. ² Studies suggest that healthy plant-based diets and vegetarian diets are also associated with lower risk of obesity, type 2 diabetes, hypertension, and cardiovascular disease. The proposed mechanisms implicated on renal benefits include the intake of lower dietary acid load, reduced sodium intake, and promotion of a healthy gut microbiome.^3,14

Life-threatening hyperkalemia is a concern among nephrologists caring for CKD patients consuming plant based diets. ² Limiting dietary potassium presents a clinical challenge because it can lead to patients not receiving enough micronutrients and a heart healthy diet. ⁶ Patiromer and SZC are newly Food and Drug Administration–approved agents to treat hyperkalemia and have been studied in patients with CKD and patients receiving renin angiotensin aldosterone system (RAAS) inhibitors. ⁷ Some of the studies of potassium binders required patients to follow a potassium restricted diet whereas others did not leading to inconclusive data. A potential use of new potassium binders is to ease dietary potassium restrictions in patients with CKD. ⁶

This case report demonstrates the ability and safety to recommend a whole food plant-based diet to patients with advanced CKD, while maintained on ACE inhibitor or angiotensin II receptor blockers (ARBs), with the adequate control of serum potassium levels using a potassium binding resin. We believe the benefits of a whole food plant-based diet should be extended to the broad range of patient with CKD, including those with advanced stages.