Reproducibility of pulse wave analysis and pulse wave velocity in patients with type 2 diabetes

Aims. Patients with type 2 diabetes have increased arterial stiffness and a high incidence of cardiovascular disease compared with non-diabetics. Arterial stiffness and central waveforms can be assessed by carotid-femoral pulse wave velocity (PWV) and pulse wave analysis (PWA) using the SphygmoCor device. These methods can potentially improve cardiovascular risk stratification in the future. However, a prerequisite is acceptable reproducibility. The objective of this study was to assess the intra-and inter-observer reproducibility of PWV and PWA indices in patients with type 2 diabetes using the SphygmoCor device. Methods. Two trained observers (A and B) each undertook two PWA and two carotid-femoral PWV recordings in random order in 20 patients with type 2 diabetes under standardized conditions on the right side of the patients. Observer A also made double recordings on the left side. The mean of the two recordings was used for inter-observer comparison. Data were analyzed by Bland-Altman plots. Results. The mean intra-observer differences (+/- 2SD) on the right side for observer A and B, respectively, were 0.0 +/- 2.8 mmHg and 0.3 +/- 3.2 mmHg (aortic systolic blood pressue (BP)), 0.0 +/- 1.2 mmHg and 0.1 +/- 1.0 mmHg (aortic diastolic BP), - 1.1 +/- 3.2% and 1.1 +/- 9.6% (central augmentation index (Aix)), - 1.6 +/- 6.6% and 0.1 +/- 9.0% (Aix normalized to heart rate 75 beats/min (Aix@HR75)) and 0.1 +/- 1.8 m/s and 0.0 +/- 1.6 m/s (PWV). The mean inter-observer differences (+/- 2SD) were - 2.6 +/- 13.0 mmHg (aortic systolic BP), - 2.1 +/- 7.4 mmHg (aortic diastolic BP), - 0.8 +/- 8.4% (Aix), - 1.5 +/- 7.4% (Aix@HR75) and - 0.3 +/- 1.6 m/s (PWV). Left-vs- right comparison showed comparable results (observer A). Conclusions. PWA and PWV assessed with the SphygmoCor device are characterized by good reproducibility in patients with type 2 diabetes.