The effect of body fat, aging, and diabetes on vertical and shear pressure in and under a waist belt and its effect on skin blood flow.

Background: Much attention has been given to the effect of pressure on skin blood flow in the feet of older people and people with diabetes. However, little attention has been paid to other areas of the body, especially under the belt at the waist where pressure might be high during body movements associated with exercise. This may be very important when devices such as heat packs are worn during the day under the belt because their safety relies on appropriate skin blood flow to dissipate the heat; in diabetes populations burns have been seen.

The influence of environmental temperature on the response of the skin to local pressure: the impact of aging and diabetes.

Background: 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.

Multiple stressors and the response of vascular endothelial cells: the effect of aging and diabetes.

Background: The present study examined the effects of local heat, global heat, and the interaction between these two endothelial stressors on the blood flow of the skin of the foot in people who are older and who have diabetes.

Methods: Subjects who were older (mean age 64.2 +/- 5.

Galvanic skin resistance--a marker for endothelial damage in diabetes.

Background: Aging and diabetes are both associated with impaired vascular endothelial function. This causes a reduction in the resting blood flow and the blood flow response to autonomic stressors. Further, skin moisture and the ability to sweat are also reduced with aging and diabetes.

Skin heat dissipation: the influence of diabetes, skin thickness, and subcutaneous fat thickness.

Background: It is well established that diabetes impairs vascular endothelial function. However, the impact of impaired endothelial function on thermal conductivity of the skin, especially in relation to a constant versus a sudden heat stress, has not been established. Further, there is some evidence that aging reduces skin dermal thickness and subcutaneous fat thickness.

The effects of skin moisture and subcutaneous fat thickness on the ability of the skin to dissipate heat in young and old subjects, with and without diabetes, at three environmental room temperatures.

The Pennes model predicts the ability of the skin to dissipate heat as a function of conductive heat transfer and blood flow. Conductive heat exchange may be affected by skin moisture and subcutaneous fat thickness, factors not considered by Pennes. In the present investigation, we sought to expand the Pennes model by examining subcutaneous fat and skin moisture as factors of heat dissipation and their effects on heat exchange and blood flow.