Purpose: Blood pressure variability (BPV) is an independent cardiovascular risk factor in CKD. Kidney transplantation (KTx) is associated with improved BP levels for kidney transplant recipient (KTRs), without evoking significant changes in donors. The aim of this study was to assess the short- and mid-time effects of KTx and donation on short-term BPV in KTRs and their respective living kidney donors.
Materials and methods: Forty KTRs and their respective donors were evaluated with 24-h ABPM (Mobil-O-Graph-NG) at baseline (1 month before), 3-months and 12-months after KTx. Standard-deviation (SD), weighted-SD (wSD), coefficient-of-variation (CV), average-real-variability (ARV) and variability independent of mean (VIM) for SBP/DBP were calculated with validated formulas.
Results: All 24-h systolic and diastolic BPV indexes studied did not change significantly from baseline to 3-month (SBP-wSD: 12.8 ± 3.0 vs 13.2 ± 3.4 mmHg, p = 0.608; SBP-ARV: 10.3 ± 2.4 vs 10.8 ± 2.6 mmHg, p = 0.463) and 12-month evaluation (SBP-wSD 12.8 ± 3.0 vs 12.1 ± 2.8; p = 0.424 and SBP-ARV: 10.3 ± 2.4 vs 10.2 ± 2.5; p = 0.615) after kidney transplantation in the KTRs.In kidney donors, all 24-h systolic BPV indices displayed a trend towards higher values at 3 months compared to baseline, but without reaching statistical significance (SBP-wSD: 12.2 ± 2.8 vs 13.6 ± 4.2 mmHg, p = 0.107 and SBP-ARV: 10.1 ± 2.1 vs 11.2 ± 3.1 mmHg, p = 0.099), the levels of 24-h systolic SBP indices at 12-months were almost identical to baseline values. 24-h diastolic BPV indices at 3-month and 12-month evaluation were similar to baseline.
Conclusion: Short-term BPV did not change significantly 3 and 12 months after kidney transplantation/donation neither in KTRs nor in living kidney donors. Longitudinal studies examining associations of BPV with adverse outcomes in these individuals are needed.
Keywords: Kidney transplantation; ambulatory blood pressure monitoring; blood pressure variability; kidney transplant recipients; living kidney donors.
What is the context? Previous studies have shown that both office and ambulatory BP levels are significantly reduced after kidney transplantation in KTRs.On the other hand, existing evidence suggests that kidney donors’ BP levels do not change significantly after kidney donation.Existing studies on BPV in KTRs are limited. The available data for living kidney donors are even fewer.What is new? This is the first study assessing short-term BPV levels in ΚTRs undergoing living donor kidney transplantation, and their respective donors in short-term and mid-term follow-up. The main findings were:All 24-h, daytime and night-time BPV indexes did not change significantly from baseline to 3- and 12-month evaluation after kidney transplantation in the KTRs.No significant changes for the 24-h, daytime and night-time BPV were observed in their respective kidney donors at the same follow-up periods.What is the impact?High BPV, which seems to remain unaltered after kidney transplantation, may be one of the many factors involved in the high cardiovascular risk observed in KTRs.Unchanged BPV levels further supports the evidence suggesting no higher risks of arrhythmias, cardiovascular events or death after living kidney donation.