Progressive Chronic Kidney Disease Cherelle Fitzclarence August 2009
Overview • Case studies • Discussion • Take home messages
Case 1 • 50 yo diabetic – 5 yr hx • Initial poor control but good last 3 years with combo of insulin and oral hypoglycaemics • Monitors own sugars • Post prandial BSL’s 150 • 8% of the surveyed group had diabetes and half of them were unaware of Dx • 30% of those surveyed had hypertension with half being unaware of Dx • 1 in 3 type 2 diabetics will develop nephropathy
Take home message • Type 2 Diabetes is now worldwide, the most common cause of end stage kidney disease • Indigenous populations have much higher rates of end stage kidney disease (ESKD) • Risk factors for ESKD – – – – – –
Hypertension Diabetes Family history Ethnicity Smoking Obesity
Case 1 • Question 2 • Which of the following is the most appropriate investigation when screening for CKD? – – – – –
24 hr urinary protein 24 hr urinary albumin excretion Urinary prot/creat ratio on a spot urine Urinary alb/creat ratio on a spot urine MSU with dipstick, spot ACR, microscopy and culture
Case 1 • Question 2 • Which of the following is the most appropriate investigation when screening for CKD? – – – – –
24 hr urinary protein 24 hr urinary albumin excretion Urinary prot/creat ratio on a spot urine Urinary alb/creat ratio on a spot urine MSU with dipstick, spot ACR, microscopy and culture
Discussion • CARI/KCAT reviewed evidence • Combo screening the best – – – – – –
U/A MSU - m,c,s ACR BP Serum creatinine (GFR)
• This should be done yearly in high risk groups – eg diabetics, ATSI • Further discussion
Take home message • Single urine dipstick for protein – limitations false positives, false negatives • Kidney function should be measured at least yearly in those at increased risk CKD • Screening should include measurement of BP, serum creatinine (GFR), MSU • Protein creatinine ratio or albumin creatinine ration
Case 1 • Question 3 • Which of the following is/are true statements concerning tests for assessing CKD? – Serum creatinine is an accurate measure of renal function and if 20mls/min excludes clinically relevant renal disease
Case 1 • Question 3 • Which of the following is/are true statements concerning tests for assessing CKD? – Serum creatinine is an accurate measure of renal function and if 20mls/min excludes clinically relevant renal disease
Discussion • Serum creatinine can stay in the normal range until more than 50% of GFR is lost • Serum creatinine is dependent on age, weight, gender and muscle mass • Small people with low muscle mass, elderly, female may have significant renal impairment despite a ‘normal’ creatinine • GFR falls over hours, days or weeks in acute renal failure • GFR falls over months, years in chronic renal failure • eGFR is used to stage kidney disease
Discussion Stage
GFR mL/min/ 1.73
Expected CM’s
1
>90
None or the primary disease process
2
60-89
None, hyperparathyroidism, increased risk CVD
3
30-59
Nocturia, anaemia, increased creat, decreased vit D, dyslipidaemia, abN extracellular volume
4
15-29
Uraemic symptoms, abnomalities electrolytes
5
150 with 4 drug therapy on board • ACEI, CCB, BB, Frusemide – Hyperlipidaemia despite statin therapy – ACR increasing despite ACEI
Case 1 • •
Question 4 In slowing the progression of renal disease and avoiding the development of malnutrition in CKD patients with an eGFR 15-30 mls/min, which of the following statements is/are correct? – Nephrotic patients need a high protein diet – Reducing proteinuria to 3g/24hrs) predicts the response to ACEI
Case 1 • •
Question 4 In slowing the progression of renal disease and avoiding the development of malnutrition in CKD patients with an eGFR 15-30 mls/min, which of the following statements is/are correct? – Nephrotic patients need a high protein diet – Reducing proteinuria to 3g/24hrs) predicts the response to ACEI
Discussion • CARI guidelines advise against excessive protein restriction for slowing renal function decline • High protein diets do little to correct the malnourished state • Control of BP can signifcantly reduce proteinuria esp ACEI, AR2B, aldosterone antagonists
Take home message • Low protein diets may slow progression CKD but only a small impact and may increase risk of malnutrition • High protein diets are not effective in treating malnutrition and may accelerate CKD • Lowering BP decreases proteinuria • Degree of preservation of renal function achieved with AHA directly proportional to decrease in proteinuria • ACEI/AR2B’s slow progression CKD more than explained just be AHA
Case 1 • •
Question 5 When a pt with T2DM is assessed for diabetic nephropathy, which of the following is correct? – The absence of proteinuria excludes diabetic nephropathy – Hypertension usually indicates the presence of concomitant macrovascular disease – The severity of diabetic nephropathy is related to the severity of hypertension – The absence of diabetic retinopathy excludes diabetic nephropathy – Kimmelstiel-Wilson lesions must be present to diagnose diabetic nephropathy
Case 1 • •
Question 5 When a pt with T2DM is assessed for diabetic nephropathy, which of the following is correct? – The absence of proteinuria excludes diabetic nephropathy – Hypertension usually indicates the presence of concomitant macrovascular disease – The severity of diabetic nephropathy is related to the severity of hypertension – The absence of diabetic retinopathy excludes diabetic nephropathy – Kimmelstiel-Wilson lesions must be present to diagnose diabetic nephropathy
Discussion •
NHANES 3 study – T2DM with creat > 150 -1/3rd had no evidence of proteinuria • Due to more of a Vasculopathy (particularly microvascular) than by classic histological changes of glomerular basement membrane thickening and mesangial expansion • Vasculopathy is associated with hypertension and may not be associated with proteinuria • Vasculopathy leads to progressive CKD, accelerated by diabetic control, hypertension, proteinuria
Take home message • Not all T2DM with CKD have proteinuria • Hypertension is common and is associated with progressive CKD • If hypertension is resistant, think RAS • Diabetic retinopathy and nephropathy are commonly but not always bound together
Case 1 • Question 6 • Which of the following is true regarding treatment aimed at slowing the progression of CKD and at preventing cardiovascular events such as AMI and CVA? – The target BP is
