Preventive Strategies for Diabetic Nephropathy

Diabetes mellitus is a global epidemic affecting more than 150 million persons and it is expected that this number is likely to double by 20251. Diabetic nephropathy is the leading cause of chronic kidney disease in patients starting renal replacement therapy and is associated with increased cardiovascular mortality. Renal involvement in patients with diabetes is defined by the appearance of low but abnormal levels (> 30 mg/ day, or 20 μg/minute) of albumin in the urine. This stage of renal involvement has been termed as microalbuminuria or incipient diabetic nephropathy. The cumulative incidence of microalbuminuria in patients with type 1 diabetes was 12.6% over 7.3 years according to European Diabetes (EURODIAB) Prospective Complications Study Group2 and 33% in an 18-year follow-up study from Denmark3. In the UK Prospective Diabetes Study (UKPDS) among patients with type 2 diabetes, the incidence of microalbuminuria was 2.0% per year and the prevalence 10 years after diagnosis was 25%4. Without specific intervention, microalbuminuria usually progresses to the next stage of diabetic nephropathy – macroalbuminuria, or “overt” nephropathy – which is characterized by urinary albumin excretion >300 mg/day or >200 μg/minute. It usually corresponds to total urinary protein excretion >0.5 g/day. Overt proteinuria usually occurs in 15 to 40% of patients with type 1 diabetes, with a peak incidence around 15 to 20 years of diabetes3,5. In patients with type 2 diabetes, the prevalence is highly variable, ranging from 5 to 20 percent4,6, if a patient has microalbuminuria, then the risk of progression to end stage renal disease (ESRD) is 20 to 40% within 15 to 20 years7,8. If a patient has macroalbuminuria, then ESRD develops in approximately 50% of cases within 10 years and in 75% within 20 years. In parallel, there is two-to-four fold increased risk for cardiovascular events and deaths for both conditions7.