Objectives: To assess the antihypertensive and antiproteinuric efficacy and safety of the angiotensin II type 1 receptor blocker telmisartan in patients with hypertension and chronic kidney disease.
Methods: A multicenter, prospective trial was performed in adults with hypertension [systolic blood pressure (SBP)/diastolic blood pressure (DBP) >130/85 mmHg), chronic renal insufficiency (serum creatinine <4.0 mg/dl), and proteinuria (>1 g/24 h). In addition to existing antihypertensive therapy, the nature and doses of which remained unchanged throughout the study, patients received once-daily telmisartan 40 mg for the first 3 months followed by forced titration to telmisartan 80 mg for the subsequent 3 months to achieve a target SBP/DBP of <130/85 mmHg. The rationale for using telmisartan was its long half-life efficacy, greater antihypertensive effect compared with valsartan or losartan, and newly discovered potential antidiabetic effect.
Results: The study was conducted in 92 patients (45 men, 47 women), of whom 60 had diabetes mellitus (54 patients with type 2 disease). Five patients discontinued prematurely: two because of hyperkalemia, two because of protocol violation, and one because of lack of efficacy. After 6 months' telmisartan treatment, office trough seated SBP was reduced by 19.6 mmHg (P<0.001) from 154.9+/-14.6 mmHg and DBP by 11.8 mmHg (P<0.001) from 91.7+/-8.1 mmHg. Seated trough SBP/DBP of <130/85 mmHg was achieved at 6 months in 34.8% of patients. Ambulatory blood pressure monitoring also demonstrated significant reductions in mean daytime SBP of 10.9 mmHg (P=0.01), night-time SBP of 12.1 mmHg (P=0.05), daytime DBP of 3.1 mmHg (P=0.05), and night-time DBP of 6.5 mmHg (P=0.05). Proteinuria decreased significantly from 3.6+/-3.4 to 2.8+/-2.8 g/24 h (P=0.01). A decrease in proteinuria depended significantly on a decrease in SBP at the end of the study (P=0.044). Each decrease in SBP of about 10 mmHg led to a decrease in proteinuria of about 0.79 g/24 h (95% CI 0.02-1.56 g/24 h). Serum creatinine increased from 1.96+/-0.79 to 2.08+/-0.89 mg/dl (P=0.01), whereas creatinine clearance did not change significantly.
Conclusions: Telmisartan effectively and safely reduced blood pressure and brought about regression of proteinuria in diabetic and nondiabetic, hypertensive, proteinuric patients with chronic kidney disease, even in those with mild-to-moderate chronic renal failure.