THE IMPACT OF BLOOD PRESSURE MANAGEMENT IN PATIENTS WITH CHRONIC KIDNEY DISEASE: A MULTICENTER PROSPECTIVE COHORT STUDY IN JAPAN

Abstract

Objective: The effect of intensive blood pressure (BP) lowering on kidney and cardiovascular outcomes among the patients with chronic kidney disease (CKD) remains unclear. We aimed to examine a preferable BP level to manage the patients with CKD. Design and method: We recruited patients with CKD under consultation with general physicians (GPs), a total of 489 GPs in 49 local medical associations. The outcomes were the renal and cardiovascular events. The renal event was defined as a doubling of the serum creatinine level, a 50 % reduction in estimated GFR or a diagnosis of end stage renal disease. We classified patients into 6 groups according to the systolic BP (SBP) level at the registration (<120, 120–129, 130–139, 140–149, 150–159, > = 160). The relationship between SBP and renal and cardiovascular events were statistically analyzed. Results: A total of 2033 patients aged 40 to 74 were participated with written informed consent. A strong correlation between SBP and the renal event was identified after adjustments for confounders. The 120–129 group had the lowest renal events, as well as <120 group (reference 120–129; <120: hazard ratio (HR) 1.30 (95% confidence interval 0.80–2.11); 130–139: HR 1.49 (1.03–2.17); 140–149; HR 1.61 (1.33–2.85); 159–160: HR 2.50 (1.68–3.78); > = 160: HR 2.17 (1.42–3.33)). Unexpectedly, regarding cardiovascular events, the 130–139 and 140–149 groups had no significant difference compared with 120–129 group, however, 150–159 and > = 160 groups had significantly large number of events (reference 120–129; <120: HR 1.29 (0.67–2.42); 130–139: HR 0.82 (0.47–1.45); 140–149: HR 1.46 (0.86–2.53); 159–160: HR 2.08 (1.20–3.66); > = 160: HR 2.80 (1.20–8.15)). Interestingly, the patients who achieved SBP levels <130 mmHg after one-year had significantly lower renal events compared with those did not (HR 0.62, (0.46–0.84)), among the patients with SBP levels > = 130 mmHg at registration. Conclusions: The SBP level <130 mmHg was associated with the lowest renal events in the patients with CKD. Furthermore, this study indicated that the patient with SBP levels > = 130 mmHg should be reduced SBP to less than 130 mmHg within a year.