Risk and prevention of diabetic nephropathy

Diabetic nephropathy is one of the most frequent causes of end-stage renal disease (ESRD), and there has been a dramatic increase in the number of patients entering renal replacement therapy in the last few years. Moreover, diabetic nephropathy is associated with elevated cardiovascular morbidity and mortality. Prevention and treatment of diabetic nephropathy is based on optimal metabolic and blood pressure control, proteinuria reduction, and renin-angiotensin-aldosterone system (RAAS) inhibition. In the normoalbuminuric patient, optimal glycemic control (HbA1c below 7.0%) plays a fundamental role in the primary prevention of ESRD. Furthermore, blood pressure levels below 130/80 mmHg are strongly recommended. In the microalbuminuric stage, strict glycemic control (HbA1c below 7.0%) likely reduces the incidence of overt nephropathy, while blood pressure values less than 130/80 mmHg are recommended. Moreover, there is evidence that inhibition of RAAS, either by angiotensin-converting-enzyme inhibitors (ACE-I) or angiotensin-receptor blockers (ARB), reduces the development of overt nephropathy, regardless of the blood pressure levels. ACE-I are recommended as the drugs of choice in type 1 diabetes, while both ACE-I and ARB are considered first-choice drugs in type 2 diabetes. Once overt proteinuria has developed, it is uncertain whether glycemic control affects the progression of nephropathy, which is strongly influenced by blood pressure and proteinuria. Optimal blood pressure levels are < 130/80 mmHg in patients with proteinuria < 1 g/day and < 120/75 mmHg in patients with proteinuria > or =1 g/day. In type 1 diabetes there is consensus on the renoprotective role of ACE-I, while in type 2 diabetes, ARB have been shown to be more effective than conventional therapy or calcium-channel blockers in slowing the progression of nephropathy. Lastly, a multifactorial therapeutic approach based on optimal glycemic control, intensive antihypertensive therapy, inhibition of RAAS, statins and aspirin is pivotal in the prevention and treatment of diabetic nephropathy