How Should This CKD Patient Eat?
Jan 26, 2024
On an ordinary afternoon, a patient with a long history of chronic kidney disease (CKD) walks into your office. When you looked up, you found that it was your old friend. You had been following him for a while. Today, all his examinations went well, but at the end of the follow-up, he suddenly asked you a question: "What should I eat to delay the progression of the disease?" You suddenly fell into thinking...
How CKD patients should eat is not only a difficult problem for ordinary doctors but also a matter of debate among world-class experts. On January 4, 2024, NEJM released a case report. What is different from the past is that in the report, the directors of nephrology from the United Kingdom and the United States "quarreled" over whether the patient should accept a low-protein diet! This article will briefly describe the case and state the opinions of the two directors, hoping to have a positive impact on your clinical practice.
case briefing
Patient, male, 63 years old, black. He had well-controlled hypertension, coronary artery disease, and CKD (stage 3b). His estimated glomerular filtration rate (eGFR) is 35ml/min/1.73㎡. His eGFR calculation formula included creatinine and cystatin C and ignored race.
Medical history information: The patient has a long history of CKD, and his proteinuria is within the non-kidney disease range. It is currently believed that the cause of his CKD is long-term hypertension. The patient's eGFR decreased steadily at a rate of 1ml/min/1.73㎡ per year. There was no history of progressive renal damage and no history of diabetes.
The patient complained that none of his family members had kidney disease. I used to smoke but stopped smoking many years ago. He had good compliance with medication and took aspirin, lisinopril, and amlodipine daily.
Physical examination: The patient's body mass index (BMI) was 25kg/㎡.
After completing the examination, the patient expressed concern about declining kidney function, expressed a desire to avoid dialysis if possible, and asked whether the progression of kidney disease could be slowed by changing dietary habits. The patient had read popular science articles and found that a strict low-protein diet might be beneficial in delaying kidney disease. He is determined to adhere to any dietary changes you recommend. Should you now recommend a low-protein diet to him, that is, a daily protein intake of <0.8g/kg?
American Director: Recommend low-protein diet
Connie M. Rhee, chief of nephrology at the David Geffen School of Medicine at UCLA and VA Greater Los Angeles Healthcare System, and Kamyar Kalantar-Zadeh, chief of nephrology at UC Irvine School of Medicine and Long Beach VA Medical Center All agreed that the patient should be recommended to receive a low-protein diet.
Existing evidence suggests that a low-protein diet can significantly reduce the risk of CKD progression and delay the initiation of renal replacement therapy. Given the patient's overwhelming enthusiasm to avoid dialysis treatment, the physician should recommend that the patient undergo a low-protein diet.
Given previous high-quality studies, for non-dialysis and non-diabetic patients with CKD stages 3 to 5, the daily protein intake should be between 0.55g and 0.60g/kg. In addition, a very low protein diet of 0.28~0.43g/kg/d, supplemented by ketogenic amino acid supplements, can further delay the progression of kidney disease. Both diets reduce the risk of kidney failure and death and prevent a decrease in quality of life.
Both animal models and clinical studies suggest that lower protein intake leads to vasoconstriction of glomerular afferent arterioles, thereby reducing intraglomerular pressure and injury, whereas a high-protein diet leads to dilation of afferent arterioles, thereby reducing intraglomerular pressure and injury. Leads to glomerular hyperfiltration and the progression of CKD. Dietary intervention has a synergistic effect with pharmacotherapy to reduce glomerular hyperfiltration. Such as renin-angiotensin-aldosterone system inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors. The above results have been confirmed by clinical studies and Meta-analysis results.
In addition, existing evidence shows that if patients can consume sufficient calories, a protein intake of 0.6~0.8g/kg/d will not lead to insufficient protein intake and protein energy consumption. Therefore, for non-dialysis-dependent CKD patients, it is safe if the protein intake is 0.8g/kg/d. Some studies have also confirmed that there is no significant abnormality in the nutritional status of CKD patients whose average protein intake is 0.66g/kg/d.
An open-label study included elderly patients with non-dialysis-dependent CKD whose GFR was 5~7ml/min/1.73㎡. These patients were randomly assigned to either supplement a vegetarian low-protein diet or start dialysis without dietary intervention. Patients in the low-protein diet group were able to delay starting dialysis (approximately 1 year) and have fewer hospitalizations than those in the dialysis group. But the risk of death is similar for both.
In summary, directors from the United States believe that the patient should be recommended to receive a low-protein diet.
British director: low-protein diet not recommended
Graham Woodrow, director of nephrology at Leeds Teaching Hospitals, Leeds NHS Trust, UK, takes a different view. He believes that specific analysis should be conducted based on the patient's situation.
For this patient, although progression may require renal replacement therapy, and at the current rate of decline in eGFR, initiation of renal replacement therapy may not take more than 20 years. However, patients were not receiving adequate medication. Currently, available drug treatments include angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), and sodium-glucose cotransporter 2 inhibitors (SGLT-2i).
There is still controversy over the safety and effectiveness of low-protein diets. Several randomized, controlled trials and several meta-analyses on protein restriction have reached varying conclusions. The medical community always has the following four concerns about research on positive results: ① The sample size is small; ② The validity of the endpoint is not high; ③ Whether it is the timing of dialysis initiation decided by clinicians; ④ Whether there are detailed biochemical test results. Currently, the largest and most robust randomized trial is the Modification of Diet in Renal Disease trial, whose intention-to-treat primary outcome analysis showed that dietary protein restriction has no benefit in slowing the progression of CKD.
A systematic review published by Hahn et al showed that in patients with advanced CKD without diabetes, a low-protein diet had little effect on the number of patients who reached end-stage renal failure compared with a normal diet. It is controversial whether a low-protein diet should be recommended to patients given its impact on quality of life, lower compliance, and possible malnutrition.
It is important to note that studies suggesting a benefit from protein restriction were generally conducted when blood pressure control was less stringent and ACEi ARB and SGLT-2i were not used. Therefore, the positive results of previous studies may not apply if protein restriction is added to current standard drug regimens.
Therefore, it may be more important for this patient to receive standard medical treatment regimens for CKD, rather than focusing on a low-protein diet.
How Does Cistanche Treat Kidney Disease?
Cistanche is a traditional Chinese herbal medicine used for centuries to treat various health conditions, including kidney disease. It is derived from the dried stems of Cistanche deserticola, a plant native to the deserts of China and Mongolia. The main active components of cistanche are phenylethanoid glycosides, echinacoside, and acteoside, which have been found to have beneficial effects on kidney health.
Kidney disease, also known as renal disease, refers to a condition in which the kidneys are not functioning properly. This can result in a buildup of waste products and toxins in the body, leading to various symptoms and complications. Cistanche may help treat kidney disease ase through several mechanisms.
Firstly, cistanche has been found to have diuretic properties, meaning it can increase urine production and help eliminate waste products from the body. This can help relieve the burden on the kidneys and prevent the buildup of toxins. By promoting diuresis, cistanche may also help Reduce high blood pressure, a common complication of kidney disease.
Moreover, cistanche has been shown to have antioxidant effects. Oxidative stress, caused by an imbalance between the production of free radicals and the body's antioxidant defenses, plays a key role in the progression of kidney disease. ies help neutralize free radicals and reduce Oxidative stress, thereby protecting the kidneys from damage. The phenylethanoid glycosides found in cistanche have been particularly effective in scavenging free radicals and inhibiting lipid peroxidation.
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.
Furthermore, cistanche has been shown to have immunomodulatory effects. In kidney disease, the immune system can be dysregulated, leading to excessive inflammation and tissue damage. Cistanche helps regulate the immune response by modulating the production and activity of immune cells, such as T cells and macrophages. This immune regulation helps reduce inflammation and prevent further damage to the kidneys.
Moreover, cistanche has been found to improve renal function by promoting the regeneration of renal tubes with cells. Renal tubular epithelial cells play a crucial role in the filtration and reabsorption of waste products and electrolytes. In kidney disease, these cells can be damaged, leading to damaged renal function. Cistanche's ability to promote the regeneration of these cells helps restore proper renal function and improve overall kidney health.
In addition to these direct effects on the kidneys, cistanche has been found to have beneficial effects on other organs and systems in the body. This holistic approach to health is particularly important in kidney disease, as the condition often affects multiple organs and systems. che has been shown to have protective effects on the liver, heart, and blood vessels, which are commonly affected by kidney disease. By promoting the health of these organs, cistanche helps improve overall kidney function and prevent further complications.
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.
