Effects of Different Types of Clothing on Circadian Rhythms of Core Temperature and Urinary Catecholamines.

Abstract

This study investigated the effects of three different types of clothing on the circadian rhythms of core temperature and urinary catecholamines. One type of clothing consisted of long-sleeved shirts, full-length trousers, and socks (Type L, 1,042 g); the second type was of half-sleeved shirts and knee-length trousers (Type H, 747 g); the third type was of Type H during the daytime and Type L during night sleep (Type M). Six healthy females participated in this study where rectal temperature, skin temperatures, heart rate, and urinary catecholamines were continuously measured for 37.5 h at an ambient temperature of 23.8 +/- 0.2 degrees C and a relative humidity of 60 +/- 5%. The results were as follows: (1) The nocturnal minimum of rectal temperature decreased significantly in the sequence Type L < Type M < Type H clothing, and 27.2 and 12.4% of the circadian amplitude were influenced by type of clothing during the daytime and the nighttime, respectively. (2) The rise of skin temperatures in the extremities increased significantly more after the subjects retired for sleep with Type M or Type H clothing than with Type L. (3) Urinary catecholamines decreased more in the evening and increased more in the morning with Type H and Type M clothing than with Type L. These results show that the circadian rhythm of core temperature, especially the nocturnal minimum value, was influenced by the type of clothing worn not only during the nighttime, but also during the daytime.

Effects of a five-hour exposure of arm and leg to a slightly cool thermal environment in the afternoon on the body temperature rhythm

“…Our past investigation (Park & Tokura 1998) demonstrated that, in the morning, the subject felt slightly cool with Type H clothing and neutral with Type L clothing, but this difference was not found in the afternoon. Moreover, the secretion of urinary catecholamines from 06:30 to 14:30 h was greater with Type H clothing but the secretion from 14:30 to 18:30 h was not significantly different between two types of clothing.…”

“…They explained the result in terms of the concept of a set-point rising slightly ahead of the rising core temperature in the morning (Aschoff 1970;Cabanac et al 1976). Moreover, the excretion of urinary ''stress'' hormone, was greater in the morning when wearing half-sleeved shirts and knee-length trousers rather than long-sleeved shirts and full-length trousers, but the excretion was not significantly different between the two types of clothing in the afternoon (Park & Tokura 1998). Whereas it is likely that exposure to cool air at any time of the waking day will exert some effects upon the circadian rectal temperature, since there will be changes in heat exchange between the individual and the environment, humans might be more sensitive to a cooler thermal environment in the morning than in the afternoon.…”

“…In our previous study (Park & Tokura 1998), it was shown that core temperature was significantly lower during night-time sleep when wearing half sleeved-shirts and knee-length trousers (Type H) compared to long sleeved-shirts and full-length trousers and socks (Type L) in an environment of 23.8 + 0.28C and 60 + 5% RH. Also, it was found that 12.4% of the amplitude of the circadian rectal temperature was due to the type of clothing worn during the daytime (after-effect), and 27.2% of the amplitude was due to the clothing worn during the night-time sleep (direct effect).…”

Effects of Different Light Intensities during the Daytime on Circadian Rhythm of Core Temperature in Humans.

“…These changes of rectal temperature might be related to sympathetic nervous activity. Our recent observation (Park and Tokura, 1998) shows that the fall of rectal temperature was positively correlated with the decrease of urinary adrenaline in the evening, suggesting that the more relaxed the sympathetic nervous system was, the greater fall the core temperature. Similar discussion was already made elsewhere (Jeong and Tokura, 1990).…”

Effects of pressure on the skin exerted by clothing on responses of urinary catecholamines and cortisol, heart rate and nocturnal urinary melatonin in humans

“…Therefore it is more relevant to study how physiological parameters respond to pressure on the skin due to the clothing worn during working hours. Park and Tokura (1998) found that the way in which the surface of the body was covered during waking hours influenced the nocturnal minimum core temperature, even if the participants slept at night wearing identical clothes. Also, the nocturnal rise of salivary melatonin was significantly suppressed when the participant slept at night under the influence of pressure upon the skin produced by foundation garments (brassiere, girdle) (Lee et al 2000;Tokura et al 2001).…”