Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma Linda, California 92350, USA.
Diabetes Technol Ther. 2009 Dec;11(12):791-8. doi: 10.1089/dia.2009.0097.
To protect against ischemia, pressure-induced vasodilation (PIV) causes an increase in skin blood flow. Endothelial dysfunction, which is commonly found in older patients and those with diabetes, and global temperatures can affect the resting blood flow in skin, which may reduce the blood flow during and after the application of local pressure. The present study investigated the PIV of the skin with exposure to three global temperatures in younger and older populations and those with diabetes.
Older subjects (n = 15, mean age 64.2 +/- 14.0 years), subjects with diabetes (n = 15, mean age 62 +/- 5.9 years, mean duration 13.2 +/- 9.1 years), or younger subjects (n = 15, mean age 25.7 +/- 2.9 years) participated. An infrared laser Dopler flow meter was used to measure skin blood flow on the bottom of the foot, lower back, and hand during and after applications of pressure at 7.5, 15, 30, 45, and 60 kPa at 16 degrees C, 24 degrees C, and 32 degrees C global temperatures.
The resting blood flow for all subjects was significantly lower in the 16 degrees C environment (P < 0.05). Blood flow in the group with diabetes was significantly lower at rest, during the application of all pressure, and after the release of pressure in all global temperatures (P < 0.05). The younger group showed a significant increase in blood flow after every pressure application, except 7.5 kPa, in all global conditions (P < 0.001). Older subjects and patients with diabetes did not have a significant reactive hyperemia, especially in the 16 degrees C environment.
The protective mechanism of PIV is severely reduced in older populations and those with diabetes, especially in colder environments where skin blood flow is already diminished.
为了防止缺血，压力诱导的血管扩张（PIV）会导致皮肤血流量增加。内皮功能障碍在老年患者和糖尿病患者中很常见，全球气温会影响皮肤的静息血流量，这可能会减少局部压力应用过程中和应用后的血流量。本研究调查了在年轻、老年和糖尿病患者中，暴露于三种全球温度下皮肤的 PIV。
老年受试者（n = 15，平均年龄 64.2 +/- 14.0 岁）、糖尿病受试者（n = 15，平均年龄 62 +/- 5.9 岁，平均病程 13.2 +/- 9.1 年）或年轻受试者（n = 15，平均年龄 25.7 +/- 2.9 岁）参加了这项研究。使用红外激光多普勒血流仪测量了在 16°C、24°C 和 32°C 三种全球温度下，足部、下背部和手部在应用 7.5、15、30、45 和 60 kPa 压力时和压力释放后的皮肤血流。
所有受试者在 16°C 环境下的静息血流明显较低（P < 0.05）。糖尿病组在所有温度下的静息、应用所有压力时和压力释放后的血流均明显较低（P < 0.05）。年轻组在所有全球条件下，除了 7.5 kPa 外，每次应用压力后血流均有显著增加（P < 0.001）。老年组和糖尿病患者在压力应用后没有明显的反应性充血，尤其是在环境温度较低的情况下。
PIV 的保护机制在老年人群和糖尿病患者中严重减弱，尤其是在皮肤血流量已经减少的寒冷环境中。
