Evaluation of periflux blood flow measurement in diabetic patients with autonomic neuropathy

The periflux blood flow (PBF) response pattern in the fingertips determined with a periflux laser Doppler flowmeter was analyzed in a standing test in which the subject was instructed to stand up from the sitting position and in Valsalva's maneuver in which respiration was held for 10 s at the maximum inspiration, and indicators such as reaction time (RT), orthostatic dysreaction rate (ODR) and PBF decreasing velocity (PDV) were established for determining autonomic abnormality. RT and ODR were significantly correlated with the change in blood pressure and pulse rate, respectively, in the standing test, and PDV was significantly correlated with beat-to-beat variation. Abnormalities were found in about half of the diabetics in the standing test and Valsalva's maneuver. These results suggested that the analysis of PBF changes in the standing and Valsalva's tests may be an easy and useful approach for clinical examination of the autonomic nervous system.