Patients with type 2 diabetes are prone to hypertension and persistent protein leakage from the kidney (microalbuminuria or macroalbuminuria). A progressive decline in renal function can lead to overt diabetic nephropathy and ESRD. The likelihood of cardiovascular disease also is increased. Control of hypertension is paramount to prevent these life-threatening complications. Agents that target the renin-angiotensin system--angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers--have been shown to be renoprotective. The groundbreaking Diabetics Exposed to Telmisartan And enalaprIL (DETAIL) trial was designed to address the absence of comparative data on the long-term effects of an angiotensin II receptor blocker versus an angiotensin-converting enzyme inhibitor on renoprotection and survival in 250 patients with hypertension and early type 2 diabetic nephropathy. The primary purpose of the 5-yr double-blind, double-dummy, randomized study was to establish whether 40 to 80 mg of telmisartan conferred similar (i.e., noninferior) renoprotection to 10 to 20 mg of enalapril as determined by the change from baseline in GFR, measured by the plasma clearance of iohexol. Secondary end points included the emergence of ESRD and all-cause mortality. Telmisartan was not inferior to enalapril in reducing the decline in GFR: Mean annual declines in GFR were 3.7 and 3.3 ml/min per 1.73 m(2) with telmisartan and enalapril, respectively. During the 5-yr study period, no patient developed a serum creatinine >200 micromol/L, and none required dialysis. There were only six deaths in each treatment group during the study, with half being due to cardiovascular events.