To study the effect of blood pressure (BP) control on the progression of renal function in elderly patients with chronic kidney disease (CKD) stages 3 and 4.

Patients aged 65 years or older in our CKD clinic with baseline CKD stages 3 and 4 and with more than one-year followup until February 2014 were included in this study. Those who had an annual loss of epidermal growth factor receptor (eGFR) for more than 5 ml·min^-1·1.73 m^-2, or reached CKD stage 5, and/or initiated renal replacement therapy were regarded as progression of CKD. Cox regression was used to analyze the effect of BP control on the progression of CKD.

A total of 118 patients [57 men, mean age (73.8±5.1) years] were enrolled in the final analysis with median baseline eGFR of 37.9 (29.3, 46.7) ml·min^-1·1.73 m^-2. The baseline BP was (137.0±18.0)/(72.5±10.3) mmHg (1 mmHg=0.133 kPa). During the median 26 months (12-94 m) follow-up period, the average treated BP was (136.2±12.1)/(70.5±6.9) mmHg. Among all the subjects, 64.4% of them reached the BP target (<140/90 mmHg) and 23.7% had progression of CKD. Treated systolic BP (HR=1.504, 95%CI 1.023-2.212) and baseline eGFR (HR=0.923, 95%CI 0.872-0.977) were independent risk factors for renal function progression in multivariate Cox analysis. Patients with treated systolic BP over 140 mmHg had higher risk to develop progression of CKD compared with those with systolic BP ≤140 mmHg (HR=2.505, 95%CI 1.090-5.756).

Tight blood pressure control is important in the routine care of elderly patients with CKD stage 3 and stage 4.

Aged; Chronic kidney disease; Blood pressure; Renal function