Overall Males n = 874 n = 213 Ln-RHI 0.67 [+ or -] 0.32 0.63 [+ or -] 0.31 Ln-RHI < 0.51 293 (33.5) 35.2 Ln-RHI < 0.44 (1Q) 223 (25.5) 25.6 Females p value n = 661 Ln-RHI 0.68 [+ or -] 0.33 0.055 Ln-RHI < 0.51 33 ns Ln-RHI < 0.44 (1Q) 25.4 ns Values are expressed as median [+ or -] 1SD; Ln-RHI: logarithmic reactive hyperemia
index; 1Q: first quartile.
Post-occlusive reactive hyperemia
(PORH), an index of microvascular function was calculated as (peak cutaneous blood flow--baseline cutaneous blood flow)/baseline cutaneous blood flow x 100 (12).
Although the exact mechanism is unknown, reactive hyperemia
is thought to occur due to the build-up of vasodilator metabolites such as endothelium-derived nitric oxide following vascular occlusion, which decreases vascular resistance leading to increased blood flow to the ischemic tissue [47, 48].
Microvascular vasodilator response indices, improving the reproducibility of the method  were calculated: delta reactive hyperemia
([DELTA]RH) as PUrh-PUb; percent change of reactive hyperemia
(% RH) as ([DELTA]RH/PUb)x100; the velocity of PORH microvascular response (Vrh) calculated through dividing of delta reactive hyperemia
by the time to peak blood flow ([DELTA]RH/t).
To explore the relationship between CHD and vascular endothelial function, CHD outpatients were recruited from our hospital and received the non-invasive detection of endothelial function (reactive hyperemia
index, RHI) with Endo-PAT2000 Diagnostic System.
Major finding: Rosuvastatin failed to improve pulmonary function overall, but significantly improved peripheral vasodilator function in patients with elevated hsCRP levels at baseline, indicated by a final reactive hyperemia
index of 2.8 vs.
In the Framingham Heart Study offspring cohort increased aortic stiffness was associated with higher forearm vascular resistance at baseline and during reactive hyperemia
, and with blunted flow reserve during hyperemia (39).
A transient increase in skin blood flow after ischemia is regulated by a protective mechanism called reactive hyperemia
The diameter of brachial artery was measured by 10 MHz transducer in longitudinal section on 2-1,5 cm above the elbow bend before and after tests with reactive hyperemia
through 30-90 seconds.
HEPA filtration was linked to a 9.4% increase in the reactive hyperemia
index (RHI), a marker of endothelial function, and a 32.6% decrease in C-reactive protein, a marker of inflammation.
After analyzing their data, the researchers found portable HEPA filters reduced the average concentrations of fine particulates inside homes by 60 pc and woodsmoke by 75 pc, and their use was associated with improved endothelial function (a 9.4 pc increase in reactive hyperemia
index) and decreased inflammation (a 32.6 pc decrease in C-reactive protein).
This blood flow occlusion produces an ischemia-induced reactive hyperemia
and, upon occlusion release, an increase in shear stress.