Browsing by Subject "sleep timing"

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  • Benedict, Christian; Brandao, Luiz Eduardo; Merikanto, Ilona; Partinen, Markku; Bjorvatn, Bjørn; Cedernaes, Jonathan (2021)
    The COVID-19 pandemic and related restrictions, such as stay-at-home-orders, have significantly altered daily routines and lifestyles. Given their importance for metabolic health, we herein compared sleep and meal timing parameters during vs. before the COVID-19 pandemic based on subjective recall, in an anonymous Swedish survey. Among 191 adults (mean age: 47 years; 77.5% females), we show that social jetlag, i.e., the mismatch in sleep midpoint between work and free days, was reduced by about 17 min during the pandemic compared with the pre-pandemic state (p < 0.001). Concomitantly, respondents’ sleep midpoint was shifted toward morning hours during workdays (p < 0.001). A later daily eating midpoint accompanied the shift in sleep timing (p = 0.001). This effect was mainly driven by a later scheduled first meal (p < 0.001). No difference in the timing of the day’s last meal was found (p = 0.814). Although our survey was limited in terms of sample size and by being cross-sectional, our results suggest that the delay in sleep timing due to the COVID-19 pandemic was accompanied by a corresponding shift in the timing of early but not late meals.
  • Pesonen, Anu-Katriina; Merikanto, Ilona; Halonen, Risto; Ujma, Peter; Makkonen, Tommi; Räikkönen, Katri; Lahti, Jari; Kuula, Liisa (2020)
    Sleep spindles are thalamocortical oscillations that contribute to sleep maintenanceand sleep-related brain plasticity. The current study is an explorative study of the cir-cadian dynamics of sleep spindles in relation to a polygenic score (PGS) for circadianpreference towards morningness. The participants represent the 17-year follow-upof a birth cohort having both genome-wide data and an ambulatory sleep electroen-cephalography measurement available (N= 154, Mean age = 16.9, SD = 0.1 years,57% girls). Based on a recent genome-wide association study, we calculated a PGSfor circadian preference towards morningness across the whole genome, including354 single-nucleotide polymorphisms. Stage 2 slow (9-12.5 Hz,N= 186 739) andfast (12.5-16 Hz,N= 135 504) sleep spindles were detected using an automatedalgorithm with individual time tags and amplitudes for each spindle. There was a sig-nificant interaction of PGS for morningness and timing of sleep spindles across thenight. These growth curve models showed a curvilinear trajectory of spindle ampli-tudes: those with a higher PGS for morningness showed higher slow spindle ampli-tudes in frontal derivations, and a faster dissipation of spindle amplitude in centralderivations. Overall, the findings provide new evidence on how individual sleep spin-dle trajectories are influenced by genetic factors associated with circadian type. Thefinding may lead to new hypotheses on the associations previously observedbetween circadian types, psychiatric problems and spindle activity.