Valsartan maintained glomerular filtration rate, whereas amlodipine increased it (+8 mL/min; P<0.01) and caused a more marked increase in the R(E)/R(A) ratio (+0.26 vs +0.13; P<0.05).
RCT (n=58)
Double-blind
randomized
Does valsartan compared to amlodipine improve renal hemodynamics in patients with mild to moderate essential hypertension?
Valsartan maintains GFR and glomerular hydrostatic pressure compared to amlodipine, which induces glomerular hyperfiltration, potentially explaining the renoprotective effects of AT1-receptor blockers.
Absolute Event Rate: 0.13% vs 0.26%
p-value: p=<.05
BACKGROUND: To elucidate the renoprotective mechanism of AT(1)-receptor blockers, we compared the effects of the AT(1)-receptor blocker valsartan with those of the calcium channel blocker amlodipine on renal hemodynamics and microcirculation. METHODS: A total of 58 patients (50.2 +/- 9.0 years) with mild to moderate essential hypertension were included in a randomized, double-blind study to receive either valsartan (80 to 160 mg) or amlodipine (5 to 10 mg). Renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured before and after 8 weeks of treatment. Glomerular hydrostatic pressure (P(Glo)) and resistances of the afferent (R(A)) and efferent (R(E)) arterioles were calculated according to the Gomez formulas. RESULTS: Blood pressure control was similar in both groups. RPF did not change with either treatment. In contrast, GFR increased with amlodipine (+8 +/- 14 mL/min; P <.01) but was preserved with valsartan. Amlodipine caused a more marked increase in the R(E)/R(A) ratio than valsartan (+0.26 +/- 0.26 v +0.13 +/- 0.24, P <.05), which was paralleled by an increase in P(Glo) in patients treated with amlodipine (+1.9 +/- 4.3 mm Hg; P <.05) but not in those treated with valsartan. CONCLUSIONS: At similar blood pressure control, valsartan maintained GFR and P(Glo), whereas amlodipine led to glomerular hyperfiltration and an increase in P(Glo). The results might explain the favorable renal outcome with AT(1)-receptor blocker therapy.
Christian Delles (2003) conducted an RCT in Mild to moderate essential hypertension (n=58). Valsartan vs. Amlodipine (5 to 10 mg) was evaluated on Change in R(E)/R(A) ratio (p=<.05). Valsartan maintained glomerular filtration rate, whereas amlodipine increased it (+8 mL/min; P<0.01) and caused a more marked increase in the R(E)/R(A) ratio (+0.26 vs +0.13; P<0.05).