Exercise and Repeated Testing Improves Accuracy of Laser Doppler Assessment of Microvascular Function Following Shortened (1-minute) Blood Flow Occlusion.

ABSTRACT

OBJECTIVES: To determine whether stability/accuracy of post-occlusive LDF following shortened, one-minute blood flow occlusion, increases in the post-exercise state or by averaging multiple measurements. METHODS: Six healthy adults (3F) underwent LDF eight times at rest and following exercise, assessing post-occlusive (one-minute occlusion) reactive hyperemia in the cutaneous microcirculation of the forefinger. Measured variables included pre- and post-occlusion steady-state perfusion (Plat1, Plat2), maximum post-occlusive perfusion (Max), PkT, and the ratio Max/Plat1. RESULTS: Stability/accuracy of all variables improved performing measurements after exercise (p < 0.05 Plat 1, Plat 2, Max and Max/Plat1). PkT and Max/Plat 1 displayed the greatest accuracy at rest (26.6 ± 5.1% and 26.6 ± 4.4% average difference, %Diff, of single measurements from individual "true" means, respectively); for these variables, %Diff improved to 19.5 ± 5.3 and 17.6 ± 2.1, respectively, following exercise. Overall, averaging multiple measurements performed at rest also improved stability/accuracy in all variables. This improvement was comparable to that obtained with a single measurement following exercise. CONCLUSIONS: A standardized exercise stimulus prior to testing significantly improves stability/accuracy of LDF following shortened, one-minute blood flow occlusion. Our results suggest the possibilities of broader applications of exercise to optimize measurements from a variety of skin perfusion methodologies.