0043 Insufficient Sleep Induces Morning Circadian Misalignment And Impairs Oral Glucose Tolerance. (27th April 2018)

• Record Type: Journal Article
• Authors: Morton, S J; Marbas, E; Knauer, O; Depner, C M; Wright, K P; Broussard, J L
• Is Part Of: Sleep. Volume 41(2018)Supplement 1
• Page Start: A18
• Page End: A18
• Publication Date: 2018-04-27
• Subjects: Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsy061.042
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Introduction: We previously reported that short sleep schedules with an early wake-time induce morning circadian misalignment and impair insulin sensitivity under ad libitum food intake conditions. However, the impact of insufficient sleep on circadian alignment and insulin sensitivity under controlled feeding conditions is unknown. Therefore, the aim of this study was to investigate whether short sleep schedules with wake-time kept constant at habitual time induces morning circadian misalignment and impairs insulin sensitivity under isocaloric food intake conditions. Methods: 18 lean, healthy, adult (10F, aged 24.4 ± 3.8y, BMI=22.3 ± 1.9kg/m 2 ; mean±SD) participated in the study. An oral glucose tolerance test (OGTT) was conducted to assess insulin sensitivity at baseline and after 3 nights of 5h sleep opportunity/night achieved by delaying bedtime by 4h without a change to habitual wake-time. Salivary melatonin was collected hourly for 6h at baseline and after insufficient sleep to assess the dim light (<8 lux) melatonin offset. When not assessing melatonin, participants were in standard (~200 lux) indoor lighting during schedule wakefulness and complete darkness during scheduled sleep. Results: Circadian melatonin offset relative to wake-time was delayed by 74 ± 17min during insufficient sleep compared to baseline (mean±SEM; p<0.001). In addition, insulin sensitivity as determined by the Matsuda Insulin Sensitivity Index, was reduced by 14 ± 6% following insufficient sleep (p<0.01). Furthermore, a significant relationship between insulin sensitivity and circadian melatonin offset relative to wake-time was observed such that the longer melatonin levels remained high after wake-time, the lower the insulin sensitivity (p<0.05). Conclusion: Our findings show that insufficient sleep achieved by delaying bedtimes with no change to habitual wake-time led to morning circadian misalignment and impaired insulin sensitivity during controlled isocaloric feeding conditions. In addition, insulin sensitivity was associated with the degree of morning circadian misalignment that occurred during short sleep. These findings support our previous work that short sleep induces circadian misalignment and may be a contributing mechanism by which insufficient sleep induces insulin resistance. Support (If Any): This work was supported by SRS CDA, K01DK110138, F32DK111161, R01HL132150, and Society in Science, The Branco Weiss Fellowship, administered by the ETH Zürich.