Reproducibility of Ambulatory Blood Pressure Variability in Untreated Hypertensive Patients

Several studies have demonstrated that blood pressure variability (BPV) is associated with an increased risk of cardiovascular morbidity and mortality. However, the optimal BPV index in terms of prognosis and reproducibility remains unclear. In this study, we aimed to evaluate the reproducibility of ambulatory BPV indices in untreated hypertensive patients. A total of 100 never-treated hypertensive patients underwent two ambulatory BP recordings within a 4-week period. For each patient, we computed BPV indices, such as the standard deviation (SD), coefficient of variation (CV), weighted SD (wSD), average real variability (ARV), time rate (TR) of BP variation, and dipping for systolic and diastolic BP. Statistical analyses were performed using the intraclass correlation coefficient (ICC) and Cohen's kappa coefficient. Reliability analysis using ICC revealed moderate reproducibility (ICC from 0.540 to 0.715) for 24 h systolic SD, wSD, CV, ARV, TR, dipping, diastolic SD, wSD, CV, and ARV and poor reproducibility (ICC < 0.5) for the 24 h diastolic TR and dipping. The ICC values for daytime BPV revealed moderate reproducibility (ICC from 0.537 to 0.672) for daytime systolic SD, CV, diastolic SD, and CV but poor reproducibility (ICC < 0.5) for daytime systolic ARV, TR, diastolic ARV, and TR. All nighttime BPV indices exhibited poor reproducibility. This study demonstrated that most 24 h and daytime BPV indices showed moderate reproducibility, whereas nighttime BPV indices and diastolic BP dipping showed poor reproducibility. Additionally, systolic BPV was more reproducible than diastolic BPV.