Effect of Telmisartan–Amlodipine Combination at Different Doses on Urinary Albumin Excretion in Hypertensive Diabetic Patients With Microalbuminuria

Background Aim of this study was to evaluate the effect of the telmisartan–amlodipine combination at different doses on urinary albumin excretion rate (UAER) in hypertensive diabetic patients with microalbuminuria. Methods After a 2-week placebo period, 300 hypertensive patients with type 2 diabetes and microalbuminuria were treated with the 40 mg of telmisartan and 2.5 mg of amlodipine combination. After 4 weeks 210 patients whose blood pressure (BP) was not controlled (BP >130/80 mm Hg) were randomized to two-dose titration regimens, one based on increasing doses of telmisartan (up to 160 mg daily) and fixed 2.5-mg dose of amlodipine, the other based on increasing doses of amlodipine (up to 10 mg daily) and fixed 40-mg dose of telmisartan. After 12 weeks the nonresponder patients were given transdermic clonidine (0.1mg/d). After 16 weeks the patients yet not controlled were discontinued, the others were followed for 48 weeks. Office BP, UAER, creatinine clearance, plasma potassium, fasting glycemia, and glycosylated hemoglobin were assessed at the end of the telmisartan (40 mg)/amlodipine (2.5 mg) treatment period and after 48 weeks of treatment. Results Similar decrease in systolic/diastolic BP values were obtained with both regimens (−24/−21, −23/−21, and −24/−21 mm Hg, all P< .001 v baseline, with increasing telmisartan; −25/−22, −25/−21, and −25/−22 mm Hg, all P< .001 v baseline with increasing amlodipine). Reductions of UAER were 47.5% (P< .01), 65.3% (P< .001), and 77% (P< .0001) for telmisartan 80, 120, and 160 mg/amlodipine 2.5 mg daily, respectively, whereas reductions of UAER were 34% (P< .03), 37% (P< .03), and 33% (P< .03) for amlodipine 5, 7.5, and 10 mg/telmisartan 40 mg daily, respectively, The difference between the two regimens was statistically significant (P< .05, P< .01, and P< .001, respectively). Conclusions These findings indicate that, at comparable levels of BP reduction, UAE decreased more in subjects treated with escalating doses of telmisartan.