Analysis and Evaluation of Patterns of Cold-induced Vasodilation Response

Abstract

Although evaluation methods for cold-induced vasodilation (CIVD), which are used for evaluating local resistance to cold stress in the fingertips, have been well reported, few studies have analyzed or evaluated patterns of CIVD response. PURPOSE: To evaluate local resistance to cold stress using response patterns obtained from the start of the first vasodilation response during fingertip immersion in ice water. METHODS: Subjects were 13 male students who had consented to participate in the present study. Subjects were not permitted to consume alcohol on the day before the test, engage in exercise on the day of the test, or eat during the two hours prior to start of the test. After 60 min resting state in a controlled environment (room temperature, 26°C; relative humidity, 40%), a thermistor thermometer was placed on the middle finger. The middle finger was immersed in ice water (0.2°C), and finger skin temperature was measured for 30 min. The mean skin temperature (MST) during immersion and the coefficient of variation (C V) obtained from its standard deviation were used as indicators for evaluation of response patterns. RESULTS: The mean values of resistance index (RI-Yoshimura), resistance index (RI-Nakamura), CIVDindex (CIVD-Takano), and CV were 7.77 ± 1.17, 8.08 ± 3.55, 8.42 ± 6.12, and 0.34 ± 0.16, respectively. Correlation coefficients between CV and temperature before immersion (TBI), MST, temperature of first rise (TFR), time of temperature rise (TTR), maximum skin temperature, minimum skin temperature, and amplitude of temperature (AT) were −0.360, −0.717**, −0.744**, 0.851**, −0.271, −0.865**, and 0.529, respectively (** P < 0.01). Correlation coefficients between CV and RI-Yoshimura, RI-Nakamura, and CIVD-Takano were −0.905**, −0.878**, −0.91**, respectively, indicating a significant (** P < 0.01) correlation in all cases. CONCLUSION: These findings suggest that MST during ice water immersion and the CV obtained from its standard deviation may be useful as indicators of CIVD response patterns and for evaluating local resistance to cold stress. In future studies, we plan to investigate relationships to factors such as sex, age, and level of exercise and training in a larger group of subjects.