Effect of telmisartan on blood pressure control and kidney function in hypertensive, proteinuric patients with chronic kidney disease.

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.