Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma Linda, California 92350, USA.
Diabetes Technol Ther. 2012 Feb;14(2):105-16. doi: 10.1089/dia.2011.0128. Epub 2011 Oct 21.
Endothelial function is known to be impaired in response to heat in people with diabetes, but little has been done to see how air humidity alters the skin blood flow response to heat.
Seventeen male and female subjects were divided in two groups, one with type 2 diabetes and the other the control subjects without diabetes, age-matched to the diabetes group. All subjects participated in a series of experiments to determine the effect of the warming of the skin by air on skin temperature and skin blood flow. On different days, skin temperature was warmed with air that was 38°C, 40°C, or 42°C for 20 min. Also, on different days, at each temperature, the air humidity was adjusted to 0%, 25%, 50%, 75%, or 100% humidity. Skin blood flow and temperature were measured throughout the exposure period. This allowed the interactions between air humidity and temperature to be assessed.
For the control subjects, the moisture in the air had no different effect on skin blood flow at air temperatures of 38°C and 40°C (analysis of variance, P>0.05), although skin blood flow progressively increased at each air temperature that was applied. But for the warmest air temperature, 42°C, although the four lower humidities had the same effect on skin blood flow, air at 100% humidity caused the largest increase in skin blood flow. In contrast, in the subjects with diabetes, blood flow was always significantly less at any air temperature applied to the skin than was observed in the control subjects (P<0.05), and skin blood flow was significantly higher for the two higher humidities for the two higher air temperatures. Skin temperature paralleled these findings.
These data show that individuals with diabetes do not tolerate moist, warm air above 50% humidity as well as controls without diabetes.
已知糖尿病患者的内皮功能会因受热而受损，但对于空气湿度如何改变皮肤对热的血流反应，人们知之甚少。
将 17 名男性和女性受试者分为两组，一组为 2 型糖尿病患者，另一组为无糖尿病的对照组，与糖尿病组年龄匹配。所有受试者均参加了一系列实验，以确定空气加热皮肤对皮肤温度和皮肤血流的影响。在不同的日子里，用 38°C、40°C 或 42°C 的空气加热皮肤 20 分钟。此外，在不同的日子里，在每个温度下，将空气湿度调节至 0%、25%、50%、75%或 100%。在整个暴露过程中测量皮肤血流和温度。这允许评估空气湿度和温度之间的相互作用。
对于对照组，在空气温度为 38°C 和 40°C 时，空气中的水分对皮肤血流没有不同的影响（方差分析，P>0.05），尽管在施加的每个空气温度下，皮肤血流都逐渐增加。但对于最温暖的空气温度 42°C，尽管四个较低的湿度对皮肤血流有相同的影响，但 100%湿度的空气会导致皮肤血流最大增加。相比之下，在糖尿病患者中，与对照组相比，任何施加到皮肤上的空气温度下的血流始终明显减少（P<0.05），并且在两个更高的空气温度下，两个更高的湿度下的皮肤血流明显更高。皮肤温度与这些发现一致。
这些数据表明，糖尿病患者对高于 50%湿度的潮湿、温暖空气的耐受性不如没有糖尿病的对照组。
