Prolonged sitting decreases cutaneous vasodilatory function regardless of ambient temperature

In Japan, people spend approximately seven hours sitting per day, which is the longest sitting time in the world. This sedentary behavior (i.e., repeated bouts of prolonged sitting) increases the risk of cardiovascular disease. Recently, a research group has reported that prolonged sitting under constant skin temperature conditions can impair cutaneous vasodilation function, and repeated local heating and cooling do not mitigate this impairment.

In the study, researchers investigated the effects of prolonged sitting on forearm cutaneous vascular function under two conditions simulating real-life environments: constant room temperature and alternating cooling and heating ambient temperatures. A total of 12 young adults (six women and six men) were included in this study.

The participants sat for 120 min under the alternating temperature condition, during which they were exposed to 18°C followed by 35°C, with this sequence repeated twice. On a separate day, they were exposed to a thermoneutral ambient temperature of 25°C for 120 min under a constant temperature condition. Cutaneous vascular function was assessed and compared between the two conditions.

The results showed that prolonged sitting decreased cutaneous vasodilation function but enhanced vasoconstrictor responsiveness. Alternating exposure to cooling and heating did not significantly suppress these changes in cutaneous vascular function. The research is published in the European Journal of Applied Physiology.

These findings indicate that temperature stimulation of the surrounding environment cannot prevent the vascular dysfunction caused by prolonged sitting. Therefore, developing more effective interventions, including those that elicit greater local skin temperature fluctuations, is crucial.