Fig 1.
Vascular reactivity assessment.
A: Instrumentation for vascular reactivity (VR) evaluation. B: Brachial artery (BA) characteristic image (top) with software tracking vessel wall over time (edge detection analysis) in the region of interest (ROI), so as to reconstruct beat-to-beat BA diameter temporal profile (bottom), before and after cuff-deflation (release of arterial occlusion). Note the beat-to-beat BA dilation after cuff-deflation. Data in the figure were obtained in a healthy subject. Blood velocity values and systolic, mean and end-diastolic diameters were determined for each analyzed beat. C: BA blood flow velocity and diameter at the time of cuff deflation (white arrow). D: Basal and VR (e.g., FMD%) data were assessed following a protocol that included 60-second (s) records in basal conditions, 300 s during arterial occlusion (cuff inflation) and 240 s after cuff deflation (reactive hyperemia, RH).
Table 1.
Vascular reactivity indexes: Equations.
Fig 2.
Age-related profiles: Brachial artery diameter and blood flow velocity.
Age-related 1th, 2.5th, 5th, 10th, 50th, 90th, 95th, 97.5th and 99th percentiles for brachial artery (BA) end-diastolic diameter (DD) (Top) and peak systolic velocity (PSV) (Bottom).
Table 2.
Demographic, anthropometric and clinical characteristics.
Table 3.
Brachial artery parameters during vascular reactivity test.
Table 4.
Vascular reactivity indexes: Levels.
Table 5.
Association between vascular reactivity indexes.
Fig 3.
Absolute values for R coefficients (ordered from highest to lowest).
Numbers in parentheses: (1 and 2): Basal vs. RH Indexes (non-adjusted and adjusted for stimulus); (3 and 4): Basal vs. Pre-release Indexes (non-adjusted and adjusted for stimulus); (5): Total Vascular Reactivity; (6): Hyperemic Stimulus Indexes; (7): Microvascular Indexes. Evans’ Empirical Classifications of Interpreting Correlation Strength by Using ‘r’ was indicated (´y´ axis). RH: Reactive hyperemia.
Fig 4.
Absolute values for R coefficients (ordered from highest to lowest).
Numbers in parentheses: (1 and 2): Basal vs. RH Indexes (non-adjusted and adjusted for stimulus); (3 and 4): Basal vs. Pre-release Indexes (non-adjusted and adjusted for stimulus); (5): Total Vascular Reactivity; (6): Hyperemic Stimulus Indexes; (7): Microvascular Indexes. Evans’ Empirical Classifications of Interpreting Correlation Strength by Using ‘r’ was indicated (´y´ axis). RH: Reactive hyperemia.
Fig 5.
Absolute values for R coefficients (ordered from highest to lowest).
Numbers in parentheses: (1 and 2): Basal vs. RH Indexes (non-adjusted and adjusted for stimulus); (3 and 4): Basal vs. Pre-release Indexes (non-adjusted and adjusted for stimulus); (5): Total Vascular Reactivity; (6): Hyperemic Stimulus Indexes; (7): Micro-vascular Indexes. Evans’ Empirical Classifications of Interpreting Correlation Strength by Using ‘r’ was indicated (´y´ axis). RH: Reactive hyperemia.
Fig 6.
Absolute values for R coefficients (ordered from highest to lowest).
Numbers in parentheses: (1 and 2): Basal vs. RH Indexes (non-adjusted and adjusted for stimulus); (3 and 4): Basal vs. Pre-release Indexes (non-adjusted and adjusted for stimulus); (5): Total Vascular Reactivity; (6): Hyperemic Stimulus Indexes; (7): Micro-vascular Indexes. Evans’ Empirical Classifications of Interpreting Correlation Strength by Using ‘r’ was indicated (´y´ axis). RH: Reactive hyperemia.
Fig 7.
Absolute values for R coefficients (ordered from highest to lowest).
Numbers in parentheses: (1 and 2): Basal vs. RH Indexes (non-adjusted and adjusted for stimulus); (3 and 4): Basal vs. Pre-release Indexes (non-adjusted and adjusted for stimulus); (5): Total Vascular Reactivity; (6): Hyperemic Stimulus Indexes; (7): Micro-vascular Indexes. Evans’ Empirical Classifications of Interpreting Correlation Strength by Using ‘r’ was indicated (´y´ axis). RH: Reactive hyperemia.
Fig 8.
Associations (simple and partial correlations [adjustment for age and sex]) between vascular reactivity indexes and brachial artery (BA) end-diastolic diameter, and systolic and diastolic blood pressure.
Fig 9.
FMD% (top) and ΔWSSPeak_Basal (bottom) age-related profiles or percentile curves for European (left) and HUNT-FIT (right) criteria. Quantitative data is in Table 6 and S1 File.
Table 6.
Vascular reactivity indexes RIs (European and HUNT-FIT criteria; detailed by decade of life).
Fig 10.
Comparative age-related profiles for FMD% considering different cut-off values to define ´low FMD%´ (based on previous reports).
Fig 11.
Comparative age-related FMD% profiles for adults (top, middle) and for children and adolescents (bottom). U.K.: United Kingdom. U.S.A.: United States of America.
Fig 12.
Comparative age-related L-FMC% and TVR% profiles.