Chronic Kidney Disease Identification and Management Amy L. Hazel, CNP Kidney & Hypertension Consultants
Chronic Kidney Disease One in 10 Americans have Chronic Kidney Disease
Chronic Kidney Disease Chronic Kidney Disease is most common in those > 70 years old
Chronic Kidney Disease Incidence of Chronic Kidney Disease is increasing most rapidly in people 65 years and older
Chronic Kidney Disease Kidney disease is the 8TH leading cause of death in the United States
Chronic Kidney Disease People with Chronic Kidney Disease are 16-40 times more likely to die than reach End-Stage Renal Disease
Chronic Kidney Disease The 1-year mortality for heart attack patients without identified Chronic Kidney Disease is 36% , compared with 51% for patients with stage 3 to 5 CKD
Chronic Kidney Disease Early detection and education can help prevent the progression of kidney disease to kidney failure
Define Chronic Kidney Disease Classify the disease by Glomerulofiltration rate, and amount of proteinuria Discuss stages of disease and its risk factors Treatment in hypertensive and diabetic renal disease Consequences of disease Medications in ckd patient We will NOT be discussing Renal Replacement therapies including transplant Acute Kidney Injury Chronic Kidney DiseaseObjectives
Chronic Kidney Disease • KDOQI (Kidney Disease Outcomes Quality Initiative) • 2002 National Kidney Foundation classification system • Stages of Chronic Kidney Disease • KDIGO (Kidney Disease: Improving Global Outcomes) • Updated, more clearly defined (2004) • Classified based on cause, GFR category and albuminuria category (2012)
Chronic Kidney Disease • Defined • Abnormalities in structure or function > 3 months with implications for health • eGFR < 60 ml/min/1.73m • A loss of half or more of the adult level of normal kidney function • albuminuria or proteinuria • Casts or blood in urine • Structural • Hydronephrosis, small kidneys, congenital kidneys, polycystic kidney disease • History of kidney transplant
Chronic Kidney Disease • What is GFR? • GFR (glomerular filtration rate) is equal to the total of the filtration rates of the functioning nephrons in the kidney. • In young adults it is approximately 120-130 mL/min/1.73 m2 and declines with age.
Chronic Kidney Disease • MDRD (Modification of Diet in Renal Disease) • Preferred method for estimating GFR using the 4-variable equation based on Serum Creatinine, age, gender, and ethnicity. • Includes body surface area • eGFRs per 1.73m2 • May be the best estimate for eGFR in older population • Current gold standard • More accurate than measured creatinine clearance from 24-hour urine collections or estimated by the Cockroft-Gault formula
Stages of disease Limitations of CR Age < 18 or >70 Gfr > 60 Extreme body size Severe malnutrition Paraplegia or quadriplegia Does not adjust for Hispanic or Asian populations Tends to overestimate gfr Urinary creatinine excretion is lower in ckd, therefore overestimating gfr from serum creatinine. Chronic Kidney Disease
Chronic Kidney Disease • Cockroft-Gault Formula • Does not includes body weight, reflecting muscle mass….main determinant of creatinine generation. • May overestimate individuals having ckd after age of 70 yrs, obese or edematous pts • Less accurate than mdrd and ckd-epi
Chronic Kidney Disease • CKD-Epidemiology Collaboration (CKD-EPI) • Uses the 4 variables found in MDRD equation, with addition of serum cystatin C to provide more accurate eGFR than MDRD in gfr >60 • May raise the number of older individuals with ckd • CKD-EPI and MDRD Study equations can therefore be applied to determine level of kidney function, regardless of a patient’s size.
Chronic Kidney Disease To use the free GFR calculator on the NKF web site: Go to www.kidney.org/gfr To download NKF’s new GFR calculator to your smartphone: Go to www.kidney.org/apps
Chronic Kidney Disease Because of greater cardiovascular disease risk and risk of disease progression at lower eGFRs, CKD Stage 3 is sub-divided into Stages 3A (45–59 mL/min/1.73 m2) and 3B (30–44 mL/min/1.73 m2).
Chronic Kidney DiseaseProteinuria • Proteinuria (most important marker of disease progression) • Ratio of the concentrations of urine albumin (mg/dl) to that of urine creatnine (g/dl) on a spot untimed specimen (or early morning?????) • Mg albumin/g creatinine (UACR) • Normal <30 mg albumin/g creatinine • Microalbuminemia > 30-300 mg albumin /g creatinine • Macroalbuminemia > 300 albumin/ g creatinine • Ckd if 2 of 3 tests are abnormal
Chronic Kidney DiseaseProteinuria • Albuminuria • Presence of excessive amounts of the protein albumin in urine • Microalbuminuria • UACR 2.5-25mg/mmol in men • UACR 3.5-35mg/mmol in women • Macroalbuminuria • UACR > 25mg/mmol in men • UACR > 35mg/mmol in women • (Urinary creatinine excretion is influenced by muscle mass, urinary creatinine excretion higher in men, on average, than women) • The preferred method: urinary albumin-to-creatinine ratio (UACR) in first void. Spot urine is acceptable if first void not practical.
Chronic Kidney DiseaseProteinuria • Proteinuria • Presence of excessive amounts of proteins in urine • Includes: albumin, low-molecular weight immunoglobulin's, lysozyme, insulin and microglobin • Total protein (mg/dl) to creatinine (g/dl) on a spot urine sample • Normal < 200 mg/g • Urine pr mg/dl 200 • Urine cr mg/dl 100 • Ratio 200/100 = 2gm protein/24hours • Increased excretion of protein leads to progression of ckd and increases cvd risks • Albuminuria and proteinuria are related, but not interchangeable.
Chronic Kidney DiseaseProteinuria • Persistant microalbuminemia: • Tx lipid disorders and /or htn • Retest in 6mo • Affect urinary albumin excretion • UTI • High protein diet • Acute febrile illness • Heavy exercise within 24 hrs • Menstruation • Drugs (NSAIDS, ACEI, ARB)
Chronic Kidney Disease • Stage 1 and 2 new guidelines American College of Physicians 2013 • Do not recommend screening for ckd in asymptomatic adults without risk factors for ckd • False positive test results, disease labeling • No benefit of early treatment • Treat hypertension in stage 1-3 ckd with acei or arb • No need to test urine for protein in adults with or without diabetes if currently taking acei or arb • Manage elevated LDL in pt with stage 1-3 ckd
Diabetes 44% of new cases of ckd Hypertension 28% of new cases of ckd Cardiovascular disease Obesity High cholesterol Lupus Family history of CKD UTI/urinary stones Systemic infections Recovery from Acute Kidney Injury (AKI) Exposure to certain drugs Socio-demographic groups Elderly minority population African American, Native American, Hispanic, and Asian. Low income/education Chronic Kidney DiseaseRisk Factors
Chronic Kidney DiseaseDiabetic Nephropathy • Diabetic Kidney Disease • Glomerulosclerosis 5-7 yr after dx • Hypertrophy and hyperfiltration in glomerulus • Strict glycemic control • ACEi • ARB
Chronic Kidney DiseaseDiabetic Nephropathy • Blood pressure control • Goal • Diabetic or Non diabetic with Albumin-to-creatinine ratio > 30 mg/g <130/80 • Diabetic or Non diabetic with albumin-to-creatinine ratio < 30gm/g <140/90 • Protein restriction, individualize • Smoking cessation
Chronic Kidney DiseaseDiabetic Nephropathy • Hypoglycemics Agents • Sulfonylureas, biguanides, DPP-4 inhibitors, GLP-1 agonists, and insulin require dose adjustments • All second generation sulfonylureas can be used in ckd pts • Glyburide not recommended with crcl < 50% • Glipizide, no adjustment
Chronic Kidney DiseaseDiabetic Nephropathy • Hypoglycemic Agents • Metformin • Lactic Acidosis • Avoid in gfr < 30 ml/min/1.73m2 • Insulin • Thiazolidinediones • Decreased renal glucogenesis • Decreased renal clearance of sulfonylureas
Chronic Kidney DiseaseHypertensive Nephropathy • Hypertensive Kidney Disease • Both a cause and consequence of the disease • Primarily: Inappropriate sodium reabsorption • Activation of RAAS • Erythropoietin administration • RAS • Extracellular fluid • Calcified arterial tree • Cardiovascular disease • Antiplatelet agents are recommended • BNP in gfr <60, interpret with caution
Chronic Kidney DiseaseHypertensive Nephropathy • Management • RAAS blockade • Reduce proteinuria • Lowers systemic BP and intraglomerular pressure • More difficult d/t increase in vascular resistance and increased blood volume • Low sodium diet (DASH diet not recommended in CKD stage 3-5) • Combination of ace/arb significantly slowed disease progression, greater reduction in proteinuria • Use of non-dihydropyridine CCB have shown to decrease proteinuria (if failed ace/arb)
Chronic Kidney DiseaseHypertensive Nephropathy • Goals • Diabetic or Non-diabetic with Albumin-to-creatinine ratio > 30 mg/g <130/80 • Diabetic or Non-diabetic with albumin-to-creatinine ratio < 30gm/g <140/90 • Delay progression of disease • Reduce cardiovascular risk
Chronic Kidney DiseaseHypertensive Nephropathy • Diuretics • Enhances antihypertensive therapy • Decreasing tubular sodium reabsorption, increasing sodium excretion, reversing ECF volume expansion and lowering bp. • Thiazides (qd) for gfr > 30 (stage 1-3) • Loops (qd-bid) for gfr < 30 (stages 4 & 5) • Potassium sparing diuretics • Risk of hyperkalemia, esp with ACEI/ARB
Chronic Kidney DiseaseComplications • Chronic Kidney Disease-Metabolic Bone Disorder (CKD-MBD) • Systemic disorder • Renal osteodystrophy • Extraskeletal (vascular) calcification • Increases in morbidity and mortality of ckd pts • Abnormalities in • Calcium • Phosphorus • Parathyroid Hormone • Vitamin D • 25(OH)D • 1,25(OH)2D • Osteoporosis (ckd 1-3) versus renal osteodystrophy (later stages)
Chronic Kidney DiseaseComplications GFR falls Rise in phosphorus decrease in calcium decreased production of calcitriol Triggers increase in Parathyroid hormone (PTH) production Increased absorption of Phosphorus in kidneys Normalize phosphorus with high PTH
Chronic Kidney DiseaseComplications • Treat complications • High phosphorus • Low Phosphorus diet • Phosphorus Binders • Correct low Vitamin D levels • Ergocalciferol/cholecalciferol • Watch for high Calcium • Active Vitamin D to suppress PTH • Seen more in late stages of disease
Chronic Kidney DiseaseComplications • Anemia (hgb < 13g/dL in males, < 12g/dL in females) • A decline in production of erythropoietin (EPO) • Not measured, assumed • Check red cell indices, absolute reticulocyte count, vitamin B12 and folate levels, and iron panel • Goal • Hemoglobin??? • Serum transferrin saturation (TSAT) > 30% • Serum ferritin <500ng/ml • Acute phase reactant, elevated with infection/inflammation
Chronic Kidney DiseaseComplications • Anemia Treatment • Iron therapy • Most common cause of anemia in ckd • Oral vs IV • Erythropoiesis-stimulating Agents (ESA) • Prevent need for transfusions • Improve QOL? • Based on weight • Not recommended in hgb > 10g/dL • Treat <10g/dL on individual basis
Chronic Kidney DiseaseComplications • Metabolic acidosis • Result of decreased production of ammonia by the kidney • Seen in stages 3-5 • Treatment: supplement Bicarbonate • Complications • Bone loss • Anorexia • Hypoalbuminemia • Insulin resistance • Muscle wasting
Sodium Restriction reduces blood pressure and may reduce albuminuria Dash diet, not rec. for ckd stage 3-5 High sodium diet limits effectiveness of ACEi/ARBs Potassium Low: loop diuretics High: Common in stage 4/5 & aldactone/ACEi/ARB/BB/NSAIDS Diet? Salt substitutes? Constipation Treatment Kayexlate education Chronic Kidney DiseaseDiet
Chronic Kidney DiseaseDiet • Phosphorus • High levels contribute to vascular calcification • High phosphorus is risk factor for cvd • high phosphorus leads to a more rapid decline in kidney function • Phosphate salts added to processed foods in form of additives and preservatives • These are > 90% absorbed versus 40-60% absorption from organic phosphorus (ie: beans, peas, nuts) • Beverages (clear) • Nutrition labeling • Treatment: Low phosphorus diet, phosphorus binders with meals
Chronic Kidney DiseaseDiet • Protein • Restriction should not be used in severe ckd • Restriction among selected patients • Restriction, controversial • 0.6-0.8g/kg per day • Provide a small reduction in rate of decline of gfr • Follow body weight, serum albumin, pre-albumin in advanced ckd • Monitored by dietician