1.6 The Bode Index Prognostic Score is an Independent Determinant of Arterial Stiffness in Chronic Obstructive Pulmonary Disease (Copd)

Background Carotid-femoral pulse wave velocity (cfPWV), a marker of cardiovascular disease, is modified by both blood pressure and changes in arterial wall properties. Current cfPWV measurement does not differentiate between effects of blood pressure and arterial wall properties. Animal studies show that the blood pressure sensitivity of arterial PWV is indicative of blood vessel remodeling. Measurement of this parameter in humans requires a forced change in blood pressure, as can be achieved by Valsalva maneuver. This study investigated a simplified method of measurement of pressure dependency of cfPWV. Methods Aortic blood pressure was measured using a validated transfer function from a brachial cuff waveform together with cfPWV in 27 subjects (15 female, 36 ± 19 years) in both the standing and supine position. The additional change in hydrostatic pressure across the carotid-femoral path length was estimated using body surface distances. Results Diastolic blood pressure changed for all subjects (standing 83 ± 8 mmHg, supine 70 ± 8 mmHg, p < 0.001). Hydrostatic change in pressure across the carotid-femoral path added a further difference of 19 ± 2 mmHg (p < 0.001). Standing cfPWV was 7.3 ± 2.2 m/s and supine cfPWV 5.2 ±1.3 m/s (p < 0.001). The resulting pressure sensitivity of cfPWV ranged from 2.7 to 39.4 cm/s/mmHg and had a correlation with age (0.2 cm/s/year, R 2 = 0.35, p < 0.001). Conclusions Measuring cfPWV and blood pressure in the standing and supine position provides a method of calculation of pressure sensitivity of cfPWV that could be easily implemented in any research laboratory or clinic and may provide predictive information beyond either cfPWV or blood pressure alone.