パジャマの素材の違いが暑熱環境での入眠過程に及ぼす影響

摘要

パジャマの素材の違いが暑熱環境での入眠過程および寝床内気候に及ぼす影響を検討した.被験者は成人男性10名とし，29℃70%RHの環境で綿のパジャマ(条件C)と冷感が持続するように開発された素材のパジャマ(条件L)を夫々着用した場合の2条件で13:00〜15:00まで就寝した.測定項目は睡眠ポリグラフ，皮膚温，寝床内気候，衣服内気候，就寝前後の温冷感，湿潤感，快適感や睡眠感，パジャマに関する主観申告であった.条件Lで条件Cよりも睡眠段階3が有意に減少したが,睡眠段階4は增加する傾向が見られた.背中の寝床内温度が睡眠前半に，腰の寝床内湿度は睡眠後半に条件Lで条件Cよりも有意に低かった.寝ていた時の主観申告では，条件Lで条件Cよりも温冷感が有意に涼しい側であった.暑熱環境下の入眠過程では，冷感が持続するように開発されたパジャマが，背中の寝床内温度，腰の寝床内湿度を低下させ，寝ている時の温冷感を改善する可能性が示唆された.%Ten healthy male subjects slept from 13:00 to 15:00 under ambient temperature and humidity maintained at 29℃ and 70%RH, respectively. They slept under two conditions: wearing a cotton pajama (C) and wearing a newly designed cold touch pajama (L). A polysomnography, skin temperature, microclimate, bed climate, and subjective sensations were obtained. The amount of stage 3 decreased significantly, while stage 4 tended to increase in L relative to C. Bed climate temperatures of the back area decreased significantly in the initial segment of sleep, and bed climate humidity in the waist area decreased in later sleep segments in L relative to C. Subjective thermal sensation during sleep was cooler in L relative to C. These results suggest that newly designed pajamas decreased bed climate temperature of the back area, reduced bed climate humidity in the waist area, and improved subjective thermal sensation during sleep onset period under mild heat exposure.