Indirect vs. Direct Assessment of Cold Induced Vasodilation
Medicine and Health Sciences
Cold-induced vasodilation (CIVD) is a phenomenon involving a counterintuitive increase in skin blood flow during cold exposure. Although CIVD was first described in 1930, CIVD mechanisms remain unknown. CIVD research has assessed vasodilation via skin temperature rather than direct assessment of skin blood flow. The study objective was to determine if laser-Doppler flux, cutaneous vascular conductance (CVC), or skin erythrocyte concentration provides better assessment of CIVD. Twelve (8 men and 4 women) healthy (via health history and vital signs) subjects’, laser- Doppler flux, erythrocyte concentration, and skin-surface temperature were measured in the index and middle finger of the left hand and index finger of the right hand, while arterial blood pressure (ABP) on a beat-by-beat basis was measured in the right ring finger. The left hand was exposed to: baseline (10 min 22-23°C air), warming (10 min 35°C water), cooling (30 min 8°C water), and recovery (15 min 22-23°C air) and the right hand to 22-23°C air throughout. Temperature CIVD was observed in all participants, with an average of 2.33±0.98 occurrences. Flux and concentration CIVDs were observed in 11 and 9 subjects with an average occurrence rate of 1.67±1.37 and 0.92±1.16, respectively. CVC increased during warming +38.1±11.8% (P=0.006), then decreased during the first 5 min of cooling -54.1±8.4% (P<0.001) but was not different by the end of cooling (P=0.143). Right hand, CVC was not initially altered, but decreased by the end of opposite hand cooling (p=0.008). Left hand index and middle finger values and responses were congruent. Cooling increased ABP by an average of 17.3±0.08% (P<0.001). These data indicate sympatholysis in immersed hand during CIVD that is not observed in the non-immersed hand. Direct measures of skin blood flow and erythrocyte concentration appear to add different aspects to the traditional indirect assessment of CIVD and allow new investigations into CIVD mechanisms.
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Gerow, Daniel OMSII; Clegg, Patrick OMSII; and Wilson, Thad E. Ph.D., "Indirect vs. Direct Assessment of Cold Induced Vasodilation" (2016). MU-COM Research Day. 36.