Renoprotective effect of telmisartan in patients with chronic kidney disease

Although the activation of the renin-angiotensin system has a major role in the development of chronic renal failure, little is known about the effect of angiotensin receptor blockers on tubulointerstitial injury. To evaluate the renoprotective effect of telmisartan, we measured urinary protein excretion, urinary liver-type fatty acid binding protein (L-FABP) excretion, and urinary collagen IV in 30 hypertensive patients with chronic kidney disease (CKD). These patients were randomly assigned to receive 40 mg/day (n = 15) or 80 mg/day (n = 15) of telmisartan before the initiation of treatment and 6 and 12 months after treatment. Both doses of telmisartan reduced systolic and diastolic blood pressure after 6 (p < 0.001) and 12 (p < 0.001) months compared with baseline levels. Blood pressure reduction rate were similar between both doses. Urinary protein, urinary L-FABP excretion, and urinary collagen IV levels declined significantly 6 (p < 0.001) and 12 (p < 0.001) months after telmisartan treatment in both doses. The reduction rate in parameters was more pronounced in patients receiving 80 mg/day compared with those taking 40 mg/day telmisartan at 12 months (p < 0.001). Telmisartan reduces proteinuria, urinary L-FABP excretion, and urinary collagen IV levels in hypertensive CKD patients.