Systolic Blood Pressure and Outcomes in Stage 3-4 Chronic Kidney Disease Patients: Evidence from a Taiwanese Cohort

• Published in: American journal of hypertension 2014-11, Vol.27 (11), p.1396-1407
• Main Authors: Chiang, Heng-Pin, Lee, Jia-Jung, Chiu, Yi-Wen, Tsai, Jer-Chia, Hung, Chi-Chih, Hwang, Shang-Jyh, Chen, Hung-Chun
• Format: Article
• Language: English
• Subjects: Aged; Antihypertensive Agents - therapeutic use; Blood pressure; Blood Pressure - drug effects; Diabetes; Disease Progression; Female; Humans; Hypertension; Hypertension - diagnosis; Hypertension - drug therapy; Hypertension - mortality; Hypertension - physiopathology; Kidney diseases; Kidney Failure, Chronic - mortality; Kidney Failure, Chronic - physiopathology; Kidney Failure, Chronic - therapy; Male; Middle Aged; Original; Proportional Hazards Models; Prospective Studies; Renal Dialysis; Renal Insufficiency, Chronic - diagnosis; Renal Insufficiency, Chronic - mortality; Renal Insufficiency, Chronic - physiopathology; Renal Insufficiency, Chronic - therapy; Risk Factors; Severity of Illness Index; Systole; Taiwan; Time Factors; Treatment Outcome
• ISSN: 0895-7061; 1941-7225
• DOI: 10.1093/ajh/hpu056

BACKGROUND Systolic blood pressure (SBP) goal for chronic kidney disease (CKD) patients is ≤140mm Hg. However, the SBP target provides no suggested lower limit, and some studies indicate that a lower SBP target may be harmful. We aimed to investigate the J-shaped relationship between SBP and clinical outcomes in CKD patients and the factors that modify this relationship. METHODS This prospective observational study enrolled 2,144 CKD stage 3-4 patients between November 2002 and May 2009 and followed them until July 2010 or death. Patients included were also enrolled within the Integrated CKD Care Program for Delaying Dialysis in a medical center and its branch hospital. Demographic, clinical, laboratory, and disease variables at baseline and end of observation were measured. RESULTS In diabetic CKD patients, the hazard ratio (HR) at SBP 96-110mm Hg vs. 111-120mm Hg was 2.52 (95% confidence interval (CI) = 1.13-5.58) for cardiovascular outcomes and was 3.14 (95% CI = 1.16-8.49) for renal outcomes. In nondiabetic CKD patients, this J-shaped relationship was not seen. Heavy proteinuria was further found to modify the J-shaped relationship in diabetic CKD patients. The HR for renal outcomes at SBP 96-110mm Hg vs. 111-120mm Hg was 4.07 (95% CI = 1.18-13.99) in diabetic CKD patients with heavy proteinuria vs. 1.72 (95% CI = 0.13-22.5) in those without heavy proteinuria. CONCLUSIONS Diabetic CKD patients have a J-shaped relationship between SBP and cardiovascular or renal outcomes, but nondiabetic CKD patients do not. The optimal SBP range might be narrower in the diabetic CKD patients.