Effect of cilnidipine on normal to marginally elevated urine albumin-creatinine ratio in asymptomatic non-diabetic hypertensive patients: An exponential decay curve analysis

Background: High-normal urinary albumin excretion has been reported to have clinical significance with respect to progression of proteinuria and hypertension. Objective: We analysed the effect of cilnidipine (10 mg/day) on morning systolic blood pressure (SBP) and urine albumin-creatinine ratio (UACR) in 16 non-diabetic hypertensive patients with a normal to marginally elevated UACR (mean ± SD 29.4 ± 21.7; range 7.572.9mg/g creatinine). Methods: Sequential home BP and UACR data were fitted to a simple exponential function as follows: y = α · e^-t/b + γ, where γ is SBP (mmHg) or UACR (mg/g creatinine); α is the extent of the SBP (mmHg)- or UACR (mg/g creatinine)-lowering effect; β (days) is the time-constant for SBP or UACR decrease; t is the number of days after the start of cilnidipine administration; and 7gamma; is the finally stabilized SBP (mmHg) or UACR (mg/g creatinine). Results: Mean ± SD morning SBP andUACR decreased by 20.4 ± 11.4mmHg and 15.2 ± 13.1 mg/g creatinine, respectively, as determined by coefficient α. The mean ± SD time-constant for UACR decrease was significantly longer than that for BP decrease (43.5 ± 22.9 vs 15.4 ± 7.1 days). UACR reduction correlated with pre-treatment UACR values (correlation coefficient [R] = 0.88, p < 0.01) but not with BP decrease. Conclusions: The present study demonstrated that cilnidipine reduced UACR in hypertensive patients with normal to marginally elevated UACR independent of its BP-lowering effect.