Diabetes and Kidney Disease Kris Bentley Renal Nurse practitioner 2018
Aims Develop an understanding of Chronic Kidney Disease Understand how diabetes impacts on your kidneys Be able to recognise the risk factors for Diabetic Nephropathy Learn strategies for diabetic patients to reduce their risk of developing Diabetic Nephropathy
Functions of the Kidney Elimination of metabolic waste Electrolyte, acid/base and fluid balance Blood pressure regulation Regulation of RBC production Regulation of bone metabolism (vit D and calcium
Diabetes is the main cause of kidney disease
Etiology Hyperglycaemia Genetic disposition Smoking Hypertension - RAS Microalbuminuria
5 stages in the development of DN 1 hypertrophic hyperfiltration 2 the quiet stage 3 microalbuminuria or initial nephropathy 4 Chronic Kidney Disease 5 End Stage Renal Disease
CKD staging in Australia GFR Stage GFR (ml/min/1.73m 2 ) 1 90 2 60-89 Normal (urine ACR mg/mmol) Male: < 2.5 Female: < 3.5 Not CKD unless haematuria, structural or pathological abnormalities present Microalbuminuria (urine ACR mg/mmol) Male: 2.5-25 Female: 3.5-35 Macroalbuminuria (urine ACR mg/mmol) Male: > 25 Female: > 35 3a 45-59 3b 30-44 4 15-29 5 <15 or on dialysis
Genetics and Ethnicity Diabetic siblings of patients with diabetes and renal disease are five times more likely to develop nephropathy than diabetic siblings of diabetic patients without renal disease. Moreover, the parents of patients with type 1 diabetes complicated by nephro -pathy have decreased survival, notably a fourfold increased risk of strokes. Familial clustering and the beneficial effects of angiotensin-converting enzyme (ACE) inhibition on diabetic nephropathy have also led to investigation of the genetics of the renin-angiotensin system. ESRD is known to be more prevalent in certain ethnic groups - there is reason for special vigilance for early signs of nephropathy in these high-risk populations, whose members presumably have a genetic predisposition to nephropathy.
Hyperglycaemia It is well established that poor metabolic control is critical in the etiology of diabetic nephropathy. Nephropathy is uncommon in patients with HbA 1c consistently <7.50%. Other hyperglycaemia-dependent metabolic abnormalities that may also play a role in the development of nephropathy include AGEs and polyols
Hypertension Hypertension is probably both a cause and an effect of diabetic nephropathy Blood pressure control is increasingly important once the renal lesion is present and as renal damage progresses.
Smoking Several lines of evidence have shown that smoking increases the risk and progression of diabetic nephropathy. In the Appropriate Blood Pressure in Diabetes Trial, 61% of enrollees were smokers. Analysis of a number of risk factors showed a 1.6-fold increased risk
Obesity and oral contraceptives BMI and weight reduction An association has been seen between use of oral contraceptives and development of DN
Screening It has become clear over time that once overt nephropathy has developed, treatment is a delaying rather than a preventive tactic. Kidney Health Check Blood Test Urine Test BP Check egfr calculated from serum creatinine Albumin / Creatinine Ratio (ACR) check for albuminuria Blood pressure maintain consistently below BP goal
Prevention & Treatment Strategies Significant progress has been made in recent years in understanding the pathophysiology, prevention, and treatment of diabetic nephropathy. Median survival after the onset of nephropathy has increased from 6 to 15 years. Benefits accrue not only in younger patients with many years of potential life expectancy but also in the elderly.
Glycaemic Control Tight glycaemic control has been shown in several studies to decrease the risk of microvascular disease in both type 1 and type 2 diabetes.
Blood Pressure Control Hypertension is more common in people with diabetes than in the nondiabetic population and is well established as a contributing cause of the microvascular complications of diabetes. Hypertension control decreases albuminuria, delays nephropathy, and improves survival in both type 1 and type 2 diabetes. ACE inhibitors should be used when microalbuminuria is present regardless of the presence or absence of hypertension in type 1 diabetes and are widely used in normotensive patients with type 2 diabetes, as well
Conclusion The single most common cause of ESRD in the world today is diabetic nephropathy, and the incidence in type 2 diabetes appears to be increasing. Several factors probably contribute to the renal damage, including hyperglycaemia and other metabolic by-products of elevated glucose, hypertension (both systemic and intrarenal), and a genetic predisposition in some patients. Patients with diabetic nephropathy usually also have diabetic retinopathy and have a much higher mortality from coronary artery disease. Critically important is attention to prevention as preferential to treatment of diabetic nephropathy. Once overt nephropathy is present, progression cannot be avoided, only delayed. The earliest clinical indicator of renal damage is microalbuminuria, which should be screened for at regular intervals with sensitive tests.