Association between blood pressure and clinical outcomes in patients undergoing maintenance hemodialysis.

BACKGROUND

Despite the clinical importance of blood pressure control in patients undergoing hemodialysis (HD), evidence on the blood pressure ranges associated with favorable outcomes remains limited and inconsistent.

METHODS

We retrospectively analyzed the data from the HD quality assessments in South Korea. Systolic blood pressure (SBP) was classified into 6 groups: VL-sys group (< 100, n = 230), L-sys (100-120, n = 2,272), R-sys (120-140, n = 17,004), H-sys (140-160, n = 17,493), VH-sys (160-180, n = 4,627), and EH-sys (≥ 180, n = 632). Diastolic blood pressure (DBP) was divided into 6 groups: EL-dia (< 60, n = 1,349), VL-dia (60-70, n = 5,460), L-dia (70-80, n = 13,361), R-dia (80-90, n = 17,442), H-dia (90-100, n = 4,211), and VH-dia (≥ 100, n = 435). Outcomes include all-cause mortality, cardiovascular events (CVE), dementia, atrial fibrillation (Afib), and fracture risk.

RESULTS

Higher SBP was associated with increased risks of all-cause mortality, CVE, dementia, and fractures compared to those of the R-sys group. Conversely, lower SBP was associated with reduced risks for all-cause mortality and CVE. The L-sys group had an adjusted hazard ratio of 0.92 (95% confidence interval [CI], 0.86-0.99) for all-cause mortality and 0.84 (95% CI, 0.76-0.93) for CVE compared with the R-sys group. Regarding DBP, in univariable analysis, survival rate was higher in the VH-dia group compared to R-dia group, but contradictive results were shown in multivariable analysis. Overall, in multivariable analysis, higher levels were associated with increased risks of all-cause mortality, CVE, and dementia, while lower DBP, particularly in the VL-dia and L-dia groups, was associated with reduced risks.

CONCLUSIONS

In our study, a SBP of 100-119 mmHg and a DBP of 60-79 mmHg were associated with improved overall survival, reduced incidence of CVE, and lower risk of dementia and fractures in patients undergoing HD.