Age-related differences in cutaneous warm sensation thresholds of human males in thermoneutral and cool environments

Abstract

The purpose of this study was to investigate age-related differences in cutaneous temperature thresholds for warm thermal sensitivity in a thermoneutral (28 °C) and in a cool environment (22 °C). Peripheral warm thresholds were measured on nine body regions (cheek, chest, abdomen, upper arm, forearm, hand, thigh, shin, and foot) using a thermal stimulator in 12 young (22±1 years) and 13 elderly male subjects (67±3 years). The results showed that: (1) mean skin temperature did not differ by age in both environments; (2) the cutaneous warm thresholds for the hand, shin, and foot were significantly higher for the elderly than for the young in both environments ( p<0.01), whereas the remaining body parts showed no age difference; (3) the most insensitive region for elderly males was the shin for both environments (p<0.01), while for young there was no statistical significant difference with T a 28 °C; (4) the shin of the elderly was seven and nine times less sensitive to warmth when compared to those of the cheek at T a 28 and 22 °C, respectively; and (5) warm thresholds were 3–4 °C greater at T a 22 °C than at 28 °C, only for the elderly males' shin and foot (p<0.05), while for young the difference between T a 22 and 28 °C was not statistically significant. The results indicate that age-related differences in cutaneous warm perception appear to be non-uniform over the body and significant on extremities; there is a greater bluntness of warm sensitivity in the cool environment for elderly males.