Paolo arbetar som sömn- och stressforskare och hans intresseområden är skiftarbete, arbetsrelaterad stress samt effekter på sömnmönster, utbrändhet, objektiva mätningar av sömnighet och konsekvenser av tupplurar och korta tupplurar på vakenhetsnivå och kognitiva föreställningar. Han har arbetat inom forskningsområdet stress och sömn sedan 2001, då han fick möjlighet att samarbeta med Sömnlaboratoriet vid Stressforskningsinstitutet, i syfte att undersöka sömnmönster på patienter med utbrändhetsdiagnos. Paolo har alltid varit mycket intresserad av sömnfysiologi och genom åren har han utvecklat en god kunskap kring tekniker för sömninspelning (PSG) och dess tolkning (sleep scoring). Han arbetar för närvarande en hel del med objektiv sömnighetsutvärderingar, främst på lastbilschaufförer och lokförare, genom den s.k. ”Karolinska Drowsiness Scoring”-metoden, en speciell teknik för tolkning och mätning av tecken på sömnighet på EEG- och EOG-inspelningar vid vakenhet.
Fil.dr. i psykologi, 2011
I urval från Stockholms universitets publikationsdatabas
Effects of late-night short-sleep on in-home polysomnography
2018. Torbjörn Åkerstedt (et al.). Journal of Sleep Research 27 (4)Artikel
Bedtime is frequently delayed by many factors in life, and a homeostatic response to the delay may compensate partly for increased time awake and shortened sleep. Because sleep becomes shorter with age and women complain of disturbed sleep more often than men, age and sex differences in the homeostatic response to a delayed bedtime may modify the homeostatic response. The purpose of the present study was to investigate the effect of late-night short-sleep (3 h with awakening at about 07:00 hours) on in-home recorded sleep in men and women in two age groups (20-30 and 65-75 years). Results (N = 59) showed that late-night short-sleep was associated with an increase in percentage of N3 sleep and a decrease in percentage of rapid eye movement sleep, as well as decreases in several measures of sleep discontinuity and rapid eye movement density. Men showed a smaller decrease in percentage of rapid eye movement sleep than women in response to late-night short-sleep, as did older individuals of both sexes compared with younger. Older men showed a weaker percentage of N3 sleep in response to late-night short-sleep than younger men. In general, men showed a greater percentage of rapid eye movement sleep and a lower percentage of N3 sleep than women, and older individuals showed a lower percentage of N3 sleep than younger. In particular, older men showed very low levels of percentage of N3 sleep. We conclude that older males show less of a homeostatic response to late-night short-sleep. This may be an indication of impaired capacity for recovery in older men. Future studies should investigate if this pattern can be linked to gender-associated differences in morbidity and mortality.
Gray Matter Volume Correlates Of Sleepiness
2018. Torbjörn Åkerstedt (et al.). Sleep 41, A58-A58Artikel
Introduction: Sleepiness is prevalent in society, often linked to disturbed sleep, shift work, stress, or diseases. It is also associated with an increased risk of accidents. Sleepiness may be related to brain metabolism and, we hypothesize that it is associated with brain gray matter (GM) volume. The present study investigated the association between sleepiness and GM volume in thalamus and insula, with a special focus on age, since both sleepiness and GM volume change with age.
Methods: In all, 84 healthy individuals participated in the experiment, of which 46 were in the age range 20–30 years and 38 ranging between 65–75 years. Data was collected in a 3 T scanner during a 5 minute anatomical scan (first in a several sessions in the scanner) in the evening after a full night of sleep. Momentary sleepiness (Karolinska Sleepiness Scale) was rated 7 times during the time in the scanner.
Results: Results showed that, in older, relative to younger adults, areas within bilateral insular cortex and thalamus GM regions of interest were negatively associated (FWE-corrected) with sleepiness (Z=4.02, p=.015 left insula and Z=4.42, p=.009 for right insula; Z=3.75, p=.020 for left thalamus and Z=4.60, p=.001 for right thalamus). Larger volume was associated with low sleepiness in the older group, but not in the older group. The effect in the insula was mainly present in the mid-anterior parts of the structure.. In addition, after applying a conservative small volume correction including all ROIs simultaneously, age-interaction effects remained significant.
Conclusion: It was concluded that self-rated momentary sleepiness in a monotonous situation is negatively associated with GM volume in areas within both thalamus and insula in older individuals. The results are in line with notions of thalamus as a driver of arousal and of anterior insula as a structure evaluating the state of the organism. Possibly, a larger GM volume in these structures may be protective against sleepiness in older individuals, a hypothesis that needs confirmation in further studies.
Thank god it's Friday - sleep improved
2017. Helena Petersen (et al.). Journal of Sleep Research 26 (5), 567-571Artikel
The weekend is usually seen as a window of recovery. Thus, sleep before a day off may be less impaired than that before a workday. However, very few polysomnographical studies have investigated this hypothesis. Therefore, the aim of the present study was to compare sleep before a workday with that before a weekend. Seventeen teachers participated. Sleep was recorded with polysomnography on one weekday night during the workweek, and on a workday (Friday) followed by a day off. Sleep diaries and actigraphs were also used. Weekend sleep showed delayed bedtime and time of rising, a longer total sleep time (45 min), increased N3 and N1, and decreased N2 and REM. Sleep spindles were reduced. The results remained after truncation to the shortest common sleep duration (5 h). The increase in N3 from weekday sleep to Friday night sleep was positively correlated with N1 change (r = 0.853, P <= 0.001), and negatively correlated with N2 change (r = -0.614, P <= 0.001). Subjective ratings showed that weekend sleep was associated with less awakening problems and lower subjective arousal during the day. The authors concluded that weekend sleep was longer, and showed increased N3 and N1. The authors suggest that the N3 increase before the day off is a result of lower stress, while the N1 increase may be an effect of sleep spindle suppression via the increase of N3 (which would suppress sleep spindles), thus reducing N2 and enhancing N1.