AMBULATORY BLOOD PRESSURE TRAJECTORIES AND BLOOD PRESSURE VARIABILITY IN KIDNEY TRANSPLANT RECIPIENTS: A COMPARATIVE STUDY AGAINST HEMODIALYSIS PATIENTS

Abstract

Objective: Hypertension is the most prevalent cardiovascular risk factor in kidney transplant recipients (KTRs). Preliminary data suggest similar ambulatory blood pressure (BP) levels in KTRs and hemodialysis (HD) patients. This is the first study evaluating in comparison the full ambulatory BP profile and short-term BP variability (BPV) in KTRs versus HD patients. Design and method: Two hundred four KTRs were matched (2:1 ratio) with 102 HD patients for age and gender. BP levels, BP trajectories and BPV indices over a 24-hour ambulatory BP monitoring (ABPM) in KTRs were compared against both the 1st and 2nd 24-hour period of a standard 48-hour ABPM in HD. To evaluate the effect of renal replacement treatment and time on ambulatory BP levels, two-way-ANOVA for repeated-measurements was performed. Results: KTRs had significantly lower SBP and pulse pressure (PP) levels compared to HD during all periods studied (24-hour SBP: KTR: 126.5 ± 12.1mmHg; HD 1st 24-hour: 132.0 ± 18.1mmHg, p = 0.006; 2nd 24-hour: 134.3 ± 17.7mmHg, p < 0.001); no significant differences were noted for DBP levels with the exception of 2nd nighttime. Repeated-measurements-ANOVA showed a significant effect of RRT modality and time on ambulatory SBP levels during all periods studied, and a significant interaction between them; the greatest between-group difference in BP (KTRs - HD in mmHg) was observed at the end of the 2nd 24-hour (-13.9mmHg, 95%CI: -21.5 to -6.2, p < 0.001). Ambulatory systolic and diastolic BPV indices were significantly lower in KTRs than in HD during all periods studied (24-hour SBP-ARV: KTRs: 9.6 ± 2.3mmHg; HD 1st 24-hour: 10.3 ± 3.0mmHg, p = 0.032; 2nd 24-hour: 11.5 ± 3.0mmHg, p < 0.001). No differences were noted in dipping pattern between the two groups. Conclusions: SBP and PP levels and trajectories, and BPV were significantly lower in KTRs compared to age- and gender-matched HD patients during all periods studied. These findings suggest a more avourable ambulatory BP profile in KTRs, in contrast to previous observations.