Overview ã…¡ Chronic kidney disease CKD usually takes a long time to develop and does not go away. the kidneys continue to work, just not as well as they should. Wastes may build up so gradually. Salts containing phosphorus and potassium may rise to unsafe levels, causing heart failure, bone problems and anemia.
Dietary factors may have an effect on the progression of kidney disease and its complications. Among CKD patients, overnutrition results in sodium and volume overload, hyperkalemia, hyperphosphatemia, and accumulation of toxic metabolites of protein degradation. Undernutrition, on the other hand, exacerbates the risk for malnutrition and wasting.
OPTIMAL DIET FOR CKD
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The optimal diet for individual CKD patients varies depending upon the estimated glomerular filtration rate (eGFR), type of kidney disease (ie, proteinuric or nonproteinuric), and the presence of other comorbidities such as diabetes, hypertension, or heart failure.
For most CKD patients, the optimal diet is one similar to the Dietary Approaches to Stop Hypertension (DASH) diet, consisting of low sodium, fruits, vegetables, legumes, fish, poultry, and whole grains. But the diet needs to be modified further depending on laboratory values including serum potassium or serum phosphorus. Clinical guidelines do not suggest any dietary modification for patients with eGFR ≥ 60 mL/min/1.73 m². Such patients should follow the same dietary recommendations as for the general population. For further information, see note, "Healthy Eating Plate".
- A daily protein intake of 0.8 g/kg. We do not recommend very-low-protein intake (<0.6 g/kg/day).
- A diet rich in vegetables.
- SODIUM. Among individuals who are hypertensive, volume overloaded, or proteinuric, we suggest a sodium intake of <2 g/day.
- For patients who are not hypertensive, volume overloaded, or proteinuric, sodium restriction to 2.3 g/day may be of benefit.
- POTASSIUM. The potassium intake should be guided by serum potassium levels. If the potassium concentration is normal, we do not restrict dietary potassium. If the potassium concentration is high, dietary potassium intake should be restricted.
- CALCIUM. Some clinicians target a total calcium intake (both dietary and medication sources) ≤ 1500 mg/day, whereas others prefer a more stringent goal of ≤1000 mg/day.
- PHOSPHORUS. Maximum phosphorus intake of 0.8 to 1 g/day, even if the serum phosphorus concentration is normal; this is because some studies suggest that dietary phosphorus intake may alter circulating fibroblast growth factor (FGF) 23 concentrations. The dietary phosphorus should be derived from sources of high biologic value, such as meats and eggs.
- Maximum caloric intake of 30 to 35 kcal/kg/day.
- Maximum fat intake <30 % of daily energy intake, with saturated fat limited to <10 % energy.
- Daily dietary fiber intake for 25 to 38 g/day.
MEDICATIONS
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Select drug dosages based on GFR, and carefully monitor kidney function when prescribing nephrotoxic medications because change in renal function alters drug metabolism.
HYPERTENSION ― ACE inhibitors (ACEi) and Angiotensin receptor blockers (ARBs) are used to reduce blood pressure in kidneys and reduce albuminuria. Dual therapy with angiotensin receptor blockers is not recommended. Use lower dose in patients with GFR less than 45 mL/minute/1.73 m²; do not routinely discontinue when GFR is less than 30 mL/minute/1.73 m² (remains nephroprotective). Follow serum potassium level as they may cause hyperkalemia. For further information see note, "Managing chronic hyperkalemia".
Calcium channel blockers (CCBs) used in combination with ACE inhibitor or angiotensin receptor blocker to control hypertension. Avoid prescribing CCBs without ACE inhibitor or ARBs, because sole use can lead to increased hyperfiltration and increased albuminuria. Diltiazem and verapamil are preferred over dihydropyridines (amlodipine [Norvasc]) because of an antiproteinuric effect. Carefully monitor for hyperkalemia if patient on spironolactone (Aldactone). See our note, "Overview of hypertension".
DIABETES ― Modify diet and encourage more than 30 minutes of physical activity 5 times per week and recommend weight loss in those with BMI greater than 25 kg/m². First line treatment for patients with type 2 diabetes is metformin and sodium-glucose cotransporter-2 (SGLT2) inhibitor. Metformin is contraindicated when GFR is less than 30 mL/minute/1.73 m² and used with caution when GFR is between 30 and 45 mL/minute/1.73 m².
SGLT2 inhibitors have nephroprotective and cardioprotective properties. Empagliflozin (Jardiance) and canagliflozin are contraindicated if estimated GFR falls below 45 mL/minute/1.73 m². Dapagliflozin (Forxiga) is contraindicated if estimated GFR falls below 60 mL/minute/1.73 m². Glucagon-like peptide 1 receptor agonists have cardioprotective and nephroprotective properties; however, the renal benefits are less well-established than those of SGLT2 inhibitors. Liraglutide (Victoza) and dulaglutide (Trulicity) can be used without dose alterations, but all glucagon-like peptide 1 receptor agonists are contraindicated in patients with estimated GFR less than 30 mL/minute/1.73 m². Second-generation sulfonylurea (Amaryl); preferred in patients with chronic kidney disease as it is metabolized primarily in the liver. If this class is used, carefully monitor blood glucose level and give conservative dosing. Most sulfonylureas are contraindicated in patients with estimated GFR less than 30 mL/minute/1.73 m². Get our note, "Precautions or contraindications for the use of antidiabetic drugs".
HYPERLIPIDEMIA ― Common among patients with chronic kidney disease. Consider statin therapy for patients with CKD who are older than 50 years or aged 18 to 50 years and at high risk for atherosclerotic cardiovascular disease (e.g., history of cardiovascular disease, stroke, or diabetes; 10-year atherosclerotic cardiovascular disease risk of greater than 10% [can be calculated here using Mobile app.]). Statin-ezetimibe combination is an option for patients with CKD. Statins or statin plus ezetimibe are not recommended for patients on dialysis.
REFERENCES
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KDIGO: 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Int Suppl. 3(1):1-150, 2013. Available at: https://kdigo.org/wp-content/uploads/2017/02/KDIGO_2012_CKD_GL.pdf
Wright M, Southcott E, MacLaughlin H, Wineberg S. Clinical practice guideline on undernutrition in chronic kidney disease. BMC Nephrol. 2019 Oct 16;20(1):370. Available at: https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-019-1530-8
Aparicio M, Chauveau P, Précigout V, Bouchet JL, Lasseur C, Combe C. Nutrition and outcome on renal replacement therapy of patients with chronic renal failure treated by a supplemented very low protein diet. J Am Soc Nephrol. 2000 Apr;11(4):708-716. Available at: https://jasn.asnjournals.org/content/11/4/708.long
Ioannidis I. Diabetes treatment in patients with renal disease: Is the landscape clear enough? World J Diabetes. 2014 Oct 15;5(5):651-8. Available at: https://www.wjgnet.com/1948-9358/full/v5/i5/651.htm