[Type 2 diabetic nephropathy: clinical course and prevention proposals 2004]

The first clinical evidence of nephropathy is the appearance of low, but abnormal, albumin levels in the urine (>30 mg/day or 20 mg/min), microalbuminuria. Without specific interventions, approximately 80% of type 1 diabetics have their urinary albumin excretion increase at a rate of 10-20%/yr to the stage of overt nephropathy or clinical albuminuria (>300 mg/24h or >200 mg/min) over 10-15 yrs, developing hypertension along the way. Approximately 30% of individuals with type 2 diabetes are found to have microalbuminuria or overt nephropathy shortly after the diagnosis of their illness, because diabetes is actually present for many years previously and because the presence of albuminuria can depend on other concomitant nephropathies, as shown by biopsy studies. Without specific intervention, 20-40% of type 2 diabetic patients with microalbuminuria progress to overt nephropathy, but 20 yrs after onset only 20% progress to end-stage renal failure (ESRD). The rates of decline in glomerular filtration rate (GFR) are highly variable from one individual to another, but they may not be substantially different between patients with type 1 and type 2 diabetes. As therapies and interventions for coronary artery disease continue to improve, more elderly type 2 diabetes patients can be expected to survive long enough to develop renal failure. The recently published Italian Society of Nephrology (SIN) guidelines for diagnosis and therapy of diabetic nephropathy present the route for the best strategies in prevention and therapy, from earlier onset to advanced ESRD.