['To evaluate whether a dose increase in angiotensin II receptor blocker (ARB) or in calcium channel blocker (CCB) is useful for chronic kidney disease (CKD) patients who do not reach their target blood pressure with ARB/CCB combined therapy.', 'The antihypertensive effect and the influence on the renal function were compared by 12 weeks each of a valsartan (VAL) dose uptitration period (VAL 160 mg + NCR 20 mg) and a nifedipine CR (NCR) dose uptitration period(VAL 80 mg+NCR 40 mg) using a crossover method in 31 CKD patients whose blood pressure did not reach the targeted BP with combined therapy with the standard dose of VAL 80 mg and NCR 20 mg.', 'The office SBP and early morning SBP at 12 weeks after the dose uptitration of NCR were significantly lower than the values at 12 weeks after the dose uptitration of VAL. The proportion of patients who achieved the targeted BP during the dose uptitration period of NCR was higher compared with that during the dose uptitration period of VAL. The urinary albumin excretion (UAE) reduced significantly during the dose titration period of NCR. However, the reduction of UAE was not significant during the dose uptitration period of VAL. The change in eGFR was not observed during either of the dose uptitration periods compared with the baseline. Significant correlation between the morning BP and UAE was observed during the dose titration period of NCR. On the other hand, the correlation was not observed during the VAL titration period.'] Is [ CCB uptitration superior to ARB uptitration in CKD patients who do not reach target blood pressure with ARB/CCB combined therapy ]?