Ryosuke Takeda1, Daiki Imai1,2, Akina Suzuki1, Akemi Ota1, Nooshin Naghavi1, Yoshihiro Yamashina1, Yoshikazu Hirasawa1, Hisayo Yokoyama1,2, Toshiaki Miyagawa1,2, Kazunobu Okazaki3,4. 1. Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan. 2. Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan. 3. Department of Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, 3-3-138 Sugimoto Sumiyoshi, Osaka, 558-8585, Japan. okazaki@sports.osaka-cu.ac.jp. 4. Research Center for Urban Health and Sports, Osaka City University, Osaka, Japan. okazaki@sports.osaka-cu.ac.jp.
Abstract
PURPOSE: It is important to know how thermal sensation is affected by normal aging under conditions that elevate core body temperature for the prevention of heat-related illness in older people. We assessed whether thermal sensation under conditions of normothermia (NT) and mild hyperthermia (HT) is lowered in older adults. METHODS: Seventeen younger (23 ± 3 years) and 12 older (71 ± 3 years) healthy men underwent measurements of the cold and warmth detection thresholds ( ± 0.1 °C/s) of their chest and forearm skin, and whole body warmth perception under NT (esophageal temperature, T es, ~36.5 °C) and HT (T es, ~37.3 °C; lower legs immersed in 42 °C water) conditions. RESULTS: Warmth detection threshold at the forearm was increased in older compared with younger participants under both NT (P = 0.006) and HT (P = 0.004) conditions. In contrast, cold detection threshold at the forearm was decreased in older compared with younger participants under NT (P = 0.001) but not HT (P = 0.16). Mild hyperthermia decreased cold detection threshold at forearm in younger participants (P = 0.001) only. There were no effects of age and condition on warmth and cold detection thresholds at chest. Whole body warmth perception increased during HT compared with NT in both groups (both, P < 0.001), and older participants had lower values than the younger group under NT (P = 0.001) and HT (P = 0.051). CONCLUSIONS: Skin warmth detection thresholds at forearm and whole body warmth perception under NT and HT and skin cold detection thresholds at forearm under NT deteriorated with aging.
PURPOSE: It is important to know how thermal sensation is affected by normal aging under conditions that elevate core body temperature for the prevention of heat-related illness in older people. We assessed whether thermal sensation under conditions of normothermia (NT) and mild hyperthermia (HT) is lowered in older adults. METHODS: Seventeen younger (23 ± 3 years) and 12 older (71 ± 3 years) healthy men underwent measurements of the cold and warmth detection thresholds ( ± 0.1 °C/s) of their chest and forearm skin, and whole body warmth perception under NT (esophageal temperature, T es, ~36.5 °C) and HT (T es, ~37.3 °C; lower legs immersed in 42 °C water) conditions. RESULTS: Warmth detection threshold at the forearm was increased in older compared with younger participants under both NT (P = 0.006) and HT (P = 0.004) conditions. In contrast, cold detection threshold at the forearm was decreased in older compared with younger participants under NT (P = 0.001) but not HT (P = 0.16). Mild hyperthermia decreased cold detection threshold at forearm in younger participants (P = 0.001) only. There were no effects of age and condition on warmth and cold detection thresholds at chest. Whole body warmth perception increased during HT compared with NT in both groups (both, P < 0.001), and older participants had lower values than the younger group under NT (P = 0.001) and HT (P = 0.051). CONCLUSIONS: Skin warmth detection thresholds at forearm and whole body warmth perception under NT and HT and skin cold detection thresholds at forearm under NT deteriorated with aging.
Authors: Jean-Marie Robine; Siu Lan K Cheung; Sophie Le Roy; Herman Van Oyen; Clare Griffiths; Jean-Pierre Michel; François Richard Herrmann Journal: C R Biol Date: 2007-12-31 Impact factor: 1.583