Ambulatory blood pressure trajectories and blood pressure variability in kidney transplant recipients: a comparative study against haemodialysis patients

Maria Korogiannou; Pantelis Sarafidis; Maria Eleni Alexandrou; Marieta P Theodorakopoulou; Eva Pella; Efstathios Xagas; Antonis Argyris; Athanase Protogerou; Aikaterini Papagianni; Ioannis N Boletis; Smaragdi Marinaki

doi:10.1093/ckj/sfab275

Ambulatory blood pressure trajectories and blood pressure variability in kidney transplant recipients: a comparative study against haemodialysis patients

Clin Kidney J. 2021 Dec 17;15(5):951-960. doi: 10.1093/ckj/sfab275. eCollection 2022 May.

Affiliations

¹ Clinic of Nephrology and Renal Transplantation, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
² Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.
³ Cardiovascular Prevention & Research Unit, Clinic & Laboratory of Pathophysiology, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.

Abstract

Background: 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 haemodialysis (HD) patients. This is the first study comparing the full ambulatory BP profile and short-term BP variability (BPV) in KTRs versus HD patients.

Methods: A total of 204 KTRs were matched (2:1 ratio) with 102 HD patients for age and gender. BP levels, BP trajectories and BPV indices over a 24-h ambulatory BP monitoring (ABPM) in KTRs were compared against both the first and second 24-h periods of a standard 48-h ABPM in HD patients. To evaluate the effect of renal replacement treatment and time on ambulatory BP levels, a two-way ANOVA for repeated measurements was performed.

Results: KTRs had significantly lower systolic blood pressure (SBP) and pulse-pressure (PP) levels compared with HD patients during all periods studied (24-h SBP: KTR: 126.5 ± 12.1 mmHg; HD first 24 h: 132.0 ± 18.1 mmHg; P = 0.006; second 24 h: 134.3 ± 17.7 mmHg; P < 0.001); no significant differences were noted for diastolic blood pressure levels with the exception of the second nighttime. Repeated measurements ANOVA showed a significant effect of renal replacement therapy 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 second 24 h [-13.9 mmHg (95% confidence interval -21.5 to -6.2); P < 0.001]. Ambulatory systolic and diastolic BPV indices were significantly lower in KTRs than in HD patients during all periods studied (24-h SBP average real variability: KTRs: 9.6 ± 2.3 mmHg; HD first 24 h: 10.3 ± 3.0 mmHg; P = 0.032; second 24 h: 11.5 ± 3.0 mmHg; 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 with age- and gender-matched HD patients during all periods studied. These findings suggest a more favourable ambulatory BP profile in KTRs, in contrast to previous observations.

Keywords: ambulatory blood pressure monitoring; blood pressure variability; end-stage kidney disease; haemodialysis; kidney transplantation.