An attempt to establish early signals of peripheral arterial disease (PAD): the use of rhythm's parameters of peripheral blood flow (RF).

: Rhythm parameters of peripheral arterial rest blood flow (RF) as a potential predictor of peripheral arterial disease (PAD) have been investigated. Three groups of subjects have been studied: a. six apparently healthy subjects; b. seven high risk (hypertension, diabetes, hypercholesterolaemia, hypertriglyceridaemia, erythrocytosis) subjects; c. four occlusive PAD selected patients with one 'pre-symptomatic' leg. RF has been measured by 'strain-gauge plethysmography' every min for 25 min, 4 times/day. Right fore-arm, right leg and left leg have been assessed. Data have been analyzed by 'single and population mean cosinor'. Significant circadian rhythms have been detected in apparently healthy subjects. Mesor and amplitude can differ according to single individual's area. Mesor is higher in upper limb. RF circadian rhythm parameters differ in subjects with various vascular risk load. Sometimes, PAD-symptomatic limb shows higher mesor than pre-symptomatic one, suggesting conditions of reactive post-ischemic hyperemia or a role of RF in PAD. Circadian dyschronia can be detected in PAD limbs but also in high risk subjects, perhaps an example of chronoprotopathology. These results suggest the possibility of a clinical use of RF rhythm parameters as predictors of vascular protopathology.