title: Influence of light exposure at nighttime on sleep development and body growth of preterm infants.
abstract: Previous studies have demonstrated that a light-dark cycle has promoted better sleep development and weight gain in preterm infants than constant light or constant darkness. However, it was unknown whether brief light exposure at night for medical treatment and nursing care would compromise the benefits brought about by such a light-dark cycle. To examine such possibility, we developed a special red LED light with a wavelength of >675 nm which preterm infants cannot perceive. Preterm infants born at <36 weeks' gestational age were randomly assigned for periodic exposure to either white or red LED light at night in a light-dark cycle after transfer from the Neonatal Intensive Care Unit to the Growing Care Unit, used for supporting infants as they mature. Activity, nighttime crying and body weight were continuously monitored from enrolment until discharge. No significant difference in rest-activity patterns, nighttime crying, or weight gain was observed between control and experimental groups. The data indicate that nursing care conducted at 3 to 4-hour intervals exposing infants to light for <15 minutes does not prevent the infants from developing circadian rest-activity patterns, or proper body growth as long as the infants are exposed to regular light-dark cycles.
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kaneshi
authors.affiliation: Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi-machi, Kodaira, Tokyo 187-8553, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Ohta
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Morioka
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Hayasaka
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Uzuki
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Akimoto
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Moriichi
authors.affiliation: Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi-machi, Kodaira, Tokyo 187-8553, Japan.|Department of Pediatrics, St. Luke's International Hospital, 9-1 Akashi-cho, Chuo-ku, Tokyo 104-8560, Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Nakagawa
authors.affiliation: Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi-machi, Kodaira, Tokyo 187-8553, Japan.|Department of Pediatrics, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Shibuya-ku, Tokyo 150-8935, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Oishi
authors.affiliation: Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi-machi, Kodaira, Tokyo 187-8553, Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Wakamatsu
authors.affiliation: Atom Medical Corp., 2-2-1 Michiba, Sakura-ku, Saitama 338-0835, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Honma
authors.affiliation: Atom Medical Corp., 2-2-1 Michiba, Sakura-ku, Saitama 338-0835, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Suma
authors.affiliation: Luceo Co., Ltd., 30-9 Ohyamakanai-cho, Itabashi-ku, Tokyo 173-0024, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Sakashita
authors.affiliation: Faculty of Sciences and Engineering, Kagoshima University, 1-21-40, Koorimoto, Kagoshima 890-0065, Japan.
authors.forename: Sei-ichi
authors.initials: S
authors.lastname: Tsujimura
authors.affiliation: Department of Human Science, Faculty of Design, Kyushu University, 9-1, Shiobaru 4-chome, Minami-ku, Fukuoka 815-8540, Japan.
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Higuchi
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Shimokawara
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Cho
authors.affiliation: Maternity and Perinatal Care Center, Hokkaido University Hospital, N15, W7, Kita-ku, Sapporo 060-8638, Japan.|Department of Obstetrics, Hokkaido University Graduate School of Medicine, N15, W7, Kitaku, Sapporo 060-8638, Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000328:Adult; D002657:Child Development / Q000528:radiation effects*; D002940:Circadian Rhythm / Q000528:radiation effects*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008027:Light; D008297:Male; D012890:Sleep / Q000528:radiation effects*