Orthostatic hypotension in kidney transplant recipients

Abstract

Introduction: Orthostatic hypotension (OH) is associated with increased morbidity and mortality. The prevalence of OH in the general population is 2–26% and is strongly associated with age. The prevalence of OH in kidney transplant recipients (KTRs) is unknown. The study aimed to investigate the prevalence of OH among KTRs and to identify factors associated with this phenomenon. Material and methods: The study was designed as a cross-sectional analysis in KTRs at a routine visit in an outpatient department. Fifty KTRs aged 60 ± 12 years (21 female and 29 male) were investigated. The kidney transplant follow-up was 72 ± 63 months (range 3–243). All subjects underwent an orthostatic test (OT). Clinical and laboratory data were also analyzed. Results: OH was diagnosed in 17 (34%) patients (the OH+ group). KTRs with OH were older (63 ± 9 vs. 54 ± 13; p = 0.01) and were more often diabetic (53% vs. 24%; p = 0.04) than patients without OH. OH+ patients had higher supine systolic blood pressure (152 ± 23 vs. 134 ± 16; p = 0.006) and higher supine pulse rate (75 ± 12 vs. 68 ± 10; p = 0.047). A higher percentage of OH+ patients were taking beta-blockers (94% vs. 70%; p = 0.048) and calcium antagonists (88% vs. 52%; p = 0.01). Pulse rate did not change significantly during the OT in patients with OH, while it increased significantly in patients without OH. Conclusions: Orthostatic hypotension is a common finding among kidney transplant patients, particularly elderly patients with coexisting diabetes. Awareness of such a high prevalence of OH should encourage physicians to perform the orthostatic test in KTRs. Concomitant pulse rate measurement and analysis of current medications may contribute to a better understanding of OH pathogenesis in an individual patient.