Presentation on theme: "Dietary Changes to Slow Chronic Kidney Disease Progression Kalani Raphael, MD MS Division of Nephrology & Hypertension University of Utah Salt Lake City."— Presentation transcript:
Dietary Changes to Slow Chronic Kidney Disease Progression Kalani Raphael, MD MS Division of Nephrology & Hypertension University of Utah Salt Lake City VA Health Care System
Stages of CKD eGFR# of AmericansMortality Risk Stage million~2x Stage million~2x Stage million25% over 5 years Stage ,00050% over 5 years Stage 5< 15600,00020% per year Levey et al. Kidney Int, 2011.
CKD - A Significant Burden 25 million Americans have CKD – 12% of US population Advancing CKD poor outcomes ESRD accounts for 6% of Medicare budget Kidney transplantation – scarce resource
Strategies to slow CKD progression ACE-I or ARB Blood pressure control < 140/90 < 130/80 Glucose control
Acid A major function of kidney is to regulate H + Avg renal acid burden = 1 meq H + per kg/day Sources of acid – Diet Protein: Red meat > fish > plant – Endogenous production Ketoacids, lactic acid
[NH 3 ] Complement Activation Kidney injury Kidney Tubular Cell Endothelin-1 H + ot Dog CKD Progression
Does reducing renal acid burden slow CKD progression?
Sodium Bicarbonate Alkaline agent Neutralizes non-volatile acid Typically prescribed when serum bicarbonate < 22 mmol/L in CKD patients – Bone protection – Reduce protein catabolism
Sodium bicarbonate may slow progression in moderate CKD Dialysis free survival Time (months) Sodium bicarbonate Control De Brito-Ashurst et al J Am Soc Neph Stage 4/5 CKD Serum bicarbonate 16 – 20
Sodium bicarbonate may slow progression in early CKD Mahajan et al Kidney International 2010 Stage 2 hypertensive CKD patients Albuminuria Normal serum bicarbonate
Summary of Sodium Bicarbonate Sodium bicarbonate reduces acid load to the kidney Reduces renal ammonia production Reduces complement-mediated kidney injury Can we reduce dietary acid load? 1.Reduce protein intake 2.Increase fruits and vegetables
Low protein diet in CKD Improves: Phosphorus BP H + Proteinuria Insulin sensitivity Disadvantages: Protein-energy malnutrition Decreased muscle Complex Inconvenient
MDRD * Study – Study A Change in GFR Low Protein (0.58 gm/kg/day) Usual Protein (1.3 gm/kg/day) Klahr et al. NEJM 1994 *Modification of Diet in Renal Disease GFR ml/min
ESRD ESRD or Death p=NS for both Levey et al AJKD 2006.
MDRD Study – Study B Low Protein (0.58 gm/kg/day Very Low Protein (0.28 gm/kg/day GFR ml/min Klahr et al. NEJM 1994
ESRD Death Menon et al AJKD 2009.
Low protein diet - Summary Theoretically beneficial Clinical trials inconclusive – Unlikely to be replicated Personal recommendation – Substitute red meat with poultry, fish, plant protein
Fruits & Vegetables – Interventional Study Key entry criteria Stage 4 CKD (GFR 15 – 29) Metabolic acidosis (Bicarb < 22) Intervention Sodium bicarbonate (1meq/kg/day) or Fruits and vegetables (reduce acid load by ½) Goraya et al Kidney Int 2013.
F/V Strategy Apples Apricots Oranges Peaches Pears Raisins Strawberries Carrots Cauliflower Eggplant Lettuce Potatoes Spinach Tomatoes Zucchini Enough given for all household members Provided free from local food bank Goraya et al Kidney Int 2013.
Due to NH 4 + Goraya et al Kidney Int 2013.
Other findings Bicarbonate and fruits/vegetables reduce urinary: 1.Albumin No hyperkalemia observed in F/V group Pts had K < 4.7 at baseline Goraya et al Kidney Int 2013.
Augmenting diet with fruits & vegetables 1.Reduces acid burden 2.Reduces renal ammonia production 3.Normalizes serum bicarbonate 4.Ameliorates kidney injury
Practical Recommendation F/V Increase fruits/veg in the diet Caution if K is > 5.0 – Reduce K with diuretics
REDUCE FRUCTOSE INTAKE
Fructose Uric Acid HTN Fructose CKD
Fructose Uric Acid Inflammation Oxidative stress Reduced NO Kidney Injury CKD Progression Other Mechanisms??
Fructose Primary sources in Western diet – High fructose corn syrup – Table sugar (sucrose) Avg American consumes 64 pounds of fructose/yr In large quantities, systemic levels high enough to be filtered by kidney
Nakayama et al. AJP Renal Phys Gersch et al AJP Renal Phys Normal rats CKD rats
Gersch et al AJP Renal Phys 2007.
p<0.001 Number of sugary soft drinks per day Shohan et al PLOS One 2008.
Low fructose diet – interventional study 28 non-DM CKD stage 2 or 3 Basal fructose intake (~60 gm/day) 6 wk low fructose (~12 gm/day) – Designed to reduce by 80% Return to basal diet for 6 wks (~53 gm/day) No diff in caloric intake Reduce consumption of sucrose-sweetened and artificially sweetened drinks & foods
Brymora et al Nephrol Dial Trans 2012.
Summary - Fructose Low fructose diet… Improves uric acid, BP May reduce renal inflammation No long-term interventional studies Its not good for you.
DIETARY RECOMMENDATIONS FOR CKD PATIENTS
Western DietDASH Diet Red meat, processedPoultry, fish Refined grainsWhole grains High-fat dairyLow-fat dairy Saturated, trans-fatsUnsaturated fats High cholesterolFresh fruit Sugary desserts/drinksVegetables
Westerner Diet & CKD progression Q1 Q2 Q3 Q4 Reference Odds Ratio Lin et al AJKD 2011.
DASHier Diet & CKD progression Q1 Q2 Q3 Q4 Reference Odds Ratio Lin et al AJKD 2011.
Conclusion High H + & fructose cause kidney injury in CKD Average American diet high in both It is sensible to increase fruits & vegetables, reduce animal protein, and eliminate sugary foods/drinks.
Summary - Dietary Recommendations for CKD 1.Stop soda, fruit drinks 2.Rare desserts 3.Fresh fruit and vegetables (monitor K + ) 4.Fish, chicken breast 5.Plant based protein, nuts 6.Less red meat, processed/canned foods 7.Low fat milk (monitor phosphorus) 8.Low salt