Aggressive treatment of
hypertension is effective in reducing both microvascular and macrovascular complications in
type 2 diabetes, and target BP less than 130/85 or 130/80 mmHg are now recommended. Inhibition of renin angiotensin aldosterone system (RAAS) plays an essential role in the treatment of
hypertension and
diabetes-related complications. Studies focusing on renal end-points suggest that
angiotensin-converting enzyme inhibitors (ACE-I) are more effective than other traditional agents in reducing the onset of clinical
proteinuria in both type 1 and type 2 diabetic patients with incipient nephropathy, mainly in normotensive ones (
secondary prevention). However, several small trials in type 2 diabetic patients with overt nephropathy (
tertiary prevention) failed to demonstrate a specific renoprotective role for ACE-I, at variance with
type 1 diabetes. Three recent large trials address the question of whether
angiotensin II receptor blockers (ARB) prevent the development of clinical
proteinuria or delay the progression of nephropathy in
type 2 diabetes. The IRMA study showed that
irbesartan is more effective than conventional
therapy in preventing the development of clinical
proteinuria and in favoring the regression to normoalbuminuria for comparable BP control in patients with incipient nephropathy. The IDNT and RENAAL trials showed that ARB are more effective than traditional
antihypertensive therapies in reducing progression toward
end-stage renal failure (ESRF) in type 2 diabetic patients with overt nephropathy independently of changes in BP. Moreover, a reduction in hospitalizations for
heart failure was demonstrated for ARB-treated patients compared with placebo. Furthermore, the LIFE study showed that
losartan is more effective than conventional
therapy in reducing cardiovascular morbidity and mortality in a cohort of diabetic patients with
hypertension and
left ventricular hypertrophy. In conclusion, ARB seem to be effective in both preventing renal damage and reducing progression toward ESRF in type 2 diabetic patients. Thus, the guidelines for the prevention and treatment of
diabetic nephropathy are now changed. In
type 1 diabetes ACE-I are the first-choice
drug; in
type 2 diabetes, ARB are considered first-choice drugs in
secondary prevention as well as ACE-I and have been now elected the unique first-choice
drug in
tertiary prevention of ESRF. Finally, ARB should be considered as the first-choice
drug in cardiovascular prevention too, as well as ACE-I.