Previous studies have confirmed that a plant-based low-protein diet can significantly delay the progression of kidney disease in patients with chronic kidney disease (CKD). Common dietary patterns include the Mediterranean diet, DASH diet, etc. Most guidelines recommend the above dietary patterns. However, one problem with a plant-based eating pattern is increased potassium intake. This in turn is related to the potential risk of hyperkalemia in CKD patients. For patients with advanced CKD, higher dietary potassium intake significantly increases the risk of hyperkalemia. So, how to reduce the risk of hyperkalemia in plant-based, low-protein CKD patients?

Recently, The American Journal of Clinical Nutrition published a clinical study, which suggested that sodium zirconium cyclosilicate (SZC) can reduce the blood potassium level of patients with CKD combined with hyperkalemia (5.1~6.5mEq/L), ensuring The patient's vegetarian intake allows them to enjoy free and healthy dietary recipes, ensuring the patient's long-term benefits.

This is a 6-week feasibility, single-arm, open-label clinical study designed to evaluate whether SZC can allow patients with CKD stages 4 to 5 to safely enjoy a healthy, plant-based, potassium-rich dietary pattern. The inclusion criteria for the study are: ①Patients with CKD stages 4 to 5, estimated glomerular filtration rate (eGFR) <29ml/min/1.73㎡; not receiving dialysis treatment; combined with hyperkalemia at baseline (5.1~6.5mEq/L) , or are normokalemic but receive sodium polystyrene sulfonate (SPS) to treat hyperkalemia. For patients receiving SPS treatment, they need to stop taking the drug for 1 week before enrolling, and they can only be enrolled after hyperkalemia occurs. Exclusion criteria for the study were severe hyperkalemia (>6.5 mEq/L), comorbid inflammatory bowel syndrome, history of hypokalemia, and inability to communicate.

The study lasted at least 6 weeks, and patients received low-protein

({{0}}.6~0.8g/kg/d) diet and low sodium (<2.3g/d) diet. The only change is that in weeks 3 to 6, the diet will be switched to a high potassium diet (potassium ion intake of at least 3700 mg/d), while in weeks 0 to 2 it will be a low potassium diet (<2300 mg/d). During the entire study period, patients received SZC treatment to control serum potassium between 3.5 and 5.0 mEq/L.

It is worth noting that the difference between weeks 2 and 3 is that more plant food intake is added to the diet, such as vegetables, fruits, beans, nuts, etc.

A total of 26 patients were included in this study, and all patients completed the 6-week study. At baseline, the mean age was 61±13 years, 65.4% were male, 17 patients had CKD stage 4, and 9 patients had CKD stage 5. The common causes of CKD are immunoglobulin A (IgA) nephropathy, diabetic nephropathy, and glomerulonephritis. Most patients are in good nutritional status at baseline, and body mass index indicates that some patients are overweight.

At the beginning of the study, between 48 and 72 hours after the patient took SZC, the patient's average serum potassium dropped from baseline and remained within the normal serum potassium level (Figure 2a), but some patients were in the hyperkalemia range. (Fig. 2b). After the 3rd week, the patient's serum potassium intake began to gradually increase, especially in the 5th and 6th weeks (Figure 2 c). As assessed by 24-h potassium ion excretion, potassium intake decreased from 0 to 3 weeks and increased from 3 to 6 weeks. During the study period, the most common dose of SZC was 10 g/d.

In terms of dietary intake, compared with the 0-3 weeks, the patients' intake of dietary fiber and 11 nutrients increased significantly during the 4-6 weeks, and the intake of fruits, vegetables, and nuts increased, while the intake of red meat increased. There was a significant decrease in intake and a significant increase in poultry and fish intake, with no significant changes in the patient's frequency or type of bowel movements. In terms of laboratory test indicators, there were no significant differences.

At the end of the study, patients had improved quality of life and physical activity compared with baseline, and reported high satisfaction with continued treatment. Regarding gastrointestinal symptoms, constipation is the most common but is rarely associated with SZC. One patient reported gout, but it was not rated as drug-related based on physician assessment.

Renin-angiotensin system inhibitors (RASi) are a common cause of elevated serum potassium in CKD patients, and in this study, the dose and type of RASi remained unchanged.

During the 48 to 72 hours after SZC treatment, the patient's serum potassium remained within the normal range. In case of hyperkalemia, there was no serum potassium >6.5 mEq/L or <3.0 mEq/L during the follow-up period. In addition, echocardiography The picture does not show the situation of QTc>550ms.

Previous studies have suggested that new potassium binders such as SZC can effectively manage hyperkalemia, but these patients need to pay attention to their potassium ion intake. However, this study suggests that even these patients with hyperkalemia may be able to eat a more liberal and healthy diet, which has never been demonstrated before. In other words, even patients with hyperkalemia in CKD stages 4 to 5 can choose a freer and healthier eating pattern when receiving SZC treatment, thus improving the patient's long-term prognosis.

Potassium ion intake mainly comes from diet, especially plant foods. In this study, patients received daily meals based on dietitian recipes that included their favorite fruits, vegetables, legumes, nuts, whole grains, meats, and/or eggs and were not affected by potassium content. And control the type or total amount of food eaten by the patient. The researchers confirmed patients' compliance with the prescribed diet by assessing potassium intake through 24-h food records and 24-h urinary potassium excretion.

Previous studies have found that potassium ion intake seems to be unrelated or weakly related to blood potassium levels; for patients with CKD stages 3 to 4, long-term (3 years or 26 weeks) intake of large amounts of fruits and vegetables will not significantly increase their potassium levels. Blood potassium. However, when patients with preexisting potassium abnormalities or hyperkalemia consume too much potassium, the patient's blood potassium levels will increase significantly. Compared with the low potassium intake group, the risk of hyperkalemia in the high potassium intake group was significantly increased by 2.5 (95% CI, 1.04~6.00; P=0.04).

In addition, this study found that RASi can effectively control patients' serum potassium without stopping the drug, suggesting that in actual clinical practice, free diet + drug treatment will not become a significant obstacle to controlling serum potassium in SZC.

Additionally, cistanche has been found to have anti-inflammatory effects. Inflammation is another key factor in the development and progression of kidney disease. Cistanche's anti-inflammatory properties help reduce the production of pro-inflammatory cytokines and inhibit the activation of inflammation mandatory pathways, thus alleviating inflammation in the kidneys.

In conclusion, cistanche is a traditional Chinese herbal medicine used for centuries to treat kidney disease. Its active components have diuretic, antioxidant, anti-inflammatory, immunomodulatory, and regenerative effects, which help improve renal function and protect the kidneys from further damage. , cistanche has beneficial effects on other organs and systems, making it a holistic approach to treating kidney disease.