Browsing by Subject "insufficient sleep"

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  • Alakuijala, Anniina; Sarkanen, Tomi; Jokela, Tomi; Partinen, Markku (2021)
    Actigraphy provides longitudinal sleep data over multiple nights. It is a less expensive and less cumbersome method for measuring sleep than polysomnography. Studies assessing accuracy of actigraphy compared to ambulatory polysomnography in different sleep-disordered patients are rare. We aimed to compare the concordance between these methods in clinical setting. We included 290 clinical measurements of 281 sleep laboratory patients (mean age 37.9 years, 182 female). Concomitant ambulatory polysomnography and actigraphy were analyzed to determine the agreement in patients with obstructive sleep apnea, narcolepsy, periodic leg movement disorder, hypersomnia, other rarer sleep disorders, or no organic sleep disorder. Bland-Altman plots showed excellent accuracy, but poor precision in single night results between the two methods in the measurement of sleep time, sleep efficiency, and sleep latency. On average, actigraphy tended to overestimate sleep time by a negligible amount, -0.13 min, 95% confidence interval [-5.9, 5.6] min in the whole sample. Overestimation was largest, -12.8 [-25.1, -0.9] min, in patients with obstructive sleep apnea. By contrast, in patients with narcolepsy, actigraphy tended to underestimate sleep time by 24.3 [12.4, 36.1] min. As for sleep efficiency, actigraphy underestimated it by 0.18 [-0.99, 1.35] % and sleep latency by 11.0 [8.5, 13.6] min compared to polysomnography. We conclude that, in measuring sleep time, actigraphy is reasonably reliable and helpful to be used for a week or two to exclude insufficient sleep in patients with the suspicion of narcolepsy. However, the effectiveness of actigraphy in determining sleep seems to decrease in subjects with low sleep efficiencies.
  • Lahtinen, Alexandra (Helsingin yliopisto, 2018)
    The need to sleep is physiologically regulated and lack of sleep results in impaired daily performance and feeling of tiredness. If sleep disturbance persists for a long time, the risk of many somatic and mental disorders increases. The study of the key molecular processes triggered by insufficient sleep could foster the assessment and enhance the methods of prevention and cure of these long-term health risks. Both insufficient and mistimed sleep have been shown to strongly affect cell transcriptome in animal models and in the studies of selected human cohorts. However, our understanding of the epigenetic modifications, particularly DNA methylation, triggered by the sleep loss remains limited. Here, we performed an epigenome-wide association study in the whole blood samples of men from the general population reporting lack of sleep and of men diagnosed with a shift work disorder. We combined the results from the two independent samples and identified a set of differentially methylated positions (DMPs) common for both cohorts. We further analyzed this set of DMPs by various computational tools, in order to explore altered biological pathways in individuals suffering from lack of sleep. As a result, we discovered a neurological pathway enriched for genes with DMPs, suggesting that curtailed sleep may result in the changes in processes related to synaptic plasticity. We also observed the loss of methylation in the majority of DMPs, in agreement with an earlier observation on the night shift workers. In order to investigate the effect of DNA methylation on gene expression, we performed correlational analyses of M values of the DMPs and the levels of corresponding gene expression. Since methylation levels might fluctuate according to the time of the blood sampling, we also studied the correlation of the DMPs with the time of the sampling. The analysis of genomic locations of the DMPs revealed enrichment of genomic loci involved in syndromes with symptoms of disturbances in visual processing and regulation of circadian rhythm. Our findings suggest that there is a distinctive pattern of genes showing diversity of epigenetic modifications in relation to insufficient sleep in men. The molecular mechanisms behind the observed associations require further investigation, both in general population based samples comprising both genders or occupational cohorts, and in experimental data.
  • Sallinen, M; Onninen, J; Ketola, K; Puttonen, S; Tuori, A; Virkkala, J; Akerstedt, T (2021)
    Experimental and epidemiological research has shown that human sleepiness is determined especially by the circadian and homeostatic processes. The present field study examined which work-related factors airline pilots perceive as causing on-duty sleepiness during short-haul and long-haul flights. In addition, the association between the perceived reasons for sleepiness and actual sleepiness levels was examined, as well as the association between reporting inadequate sleep causing sleepiness and actual sleep-wake history. The study sample consisted of 29 long-haul (LH) pilots, 28 short-haul (SH) pilots, and 29 mixed fleet pilots (flying both SH and LH flights), each of whom participated in a 2-month field measurement period, yielding a total of 765 SH and 494 LH flight duty periods (FDPs) for analyses (FDP, a period between the start of a duty and the end of the last flight of that duty). The self-reports of sleepiness inducers were collected at the end of each FDP by an electronic select menu. On-duty sleepiness was rated at each flight phase by the Karolinska Sleepiness Scale (KSS). The sleep-wake data was collected by a diary and actigraph. The results showed that "FDP timing" and "inadequate sleep" were the most frequently reported reasons for on-duty sleepiness out of the seven options provided, regardless of FDP type (SH, LH). Reporting these reasons significantly increased the odds of increased on-duty sleepiness (KSS >= 7), except for reporting "inadequate sleep" during LH FDPs. Reporting "inadequate sleep" was also associated with increased odds of a reduced sleep-wake ratio (total sleep time/amount of wakefulness