Bedtime variability also worsens metabolic health in non-shift workers
Bitesize research – a brief article summary from the Sleepio team:
Taylor et al. (2016). Bedtime variability and metabolic health in midlife women: the SWAN sleep study. Sleep, 39: 457–465. http://dx.doi.org/10.5665/sleep.5464
Previous studies have demonstrated negative consequences of shift work on metabolic health. However, the impact of fluctuations in sleep timing outside of shift work is less clear. In this study, the association of sleep timing with indicators of metabolic health, i.e. body mass index (BMI) and insulin resistance, was assessed in 338 middle-aged women. Greater bedtime variability and bedtime delay, as assessed with a sleep diary on workdays and free days, were associated with a higher insulin resistance cross-sectionally (respectively β=0.128; P=0.007 and β=0.110; P=0.013). In addition, a greater bedtime advance was associated with a higher BMI (β=0.095; P=0.047). Prospectively, only a greater bedtime delay was associated with higher insulin resistance (β=0.152; P=0.003). This suggests that a large variation in bedtime between workdays and free days might impair metabolic health, both in shift workers and non-shift workers.