Total Sleep Time Duration Research Articles

Short and long sleep duration and associated factors in pre-adolescence and early adulthood: evidence from the 1993 Pelotas birth cohort study

ObjectiveThe objective of the present study was to investigate the associated factors with short and long sleep duration at ages 11 (pre-adolescence) and 22 years old (early adulthood). MethodsParticipants of the 1993 Pelotas birth cohort with self-reported sleep records at 11 (n = 4442) and 22 (n = 3800) years were included. The total sleep time duration was categorised as short (<9 h for 11 years and <7 h for 22 years), long (>11 for 11 years and >9 for 22 years) and recommended according to the National Sleep Foundation criteria. Multinomial regression analyses were applied according to a hierarchical approach in order to investigate the associated factors with sleep duration patterns. All analyses were stratified by sex. ResultsHigher income was associated with higher odds of short sleep duration in 11-year-old boys [OR = 1.54 (CI95%: 1.08; 2.19)] and girls [OR = 1.45 (CI95%: 1.03; 2.06)] and also with lower odds of long sleep duration in both ages. At 22 years, common mental health disorders were associated with higher odds of short sleep duration in both men [OR = 1.56 (CI95%: 1.18; 2.06)] and women [OR = 1.48 (CI95%: 1.11; 1.99)]. Sleep duration was also related to screen time and physical activity showing different association patterns according to sex and age. ConclusionsDifferent factors may be associated with sleep duration patterns in pre-adolescence and early adulthood. Our results emphasise the importance of considering stratification analyses to identify associated factors with sleep duration since they may vary according to age and sex.

1214 Higher Bedroom Temperature Associated With Poorer Sleep: Data From Over 3.75 Million Nights

Abstract Introduction Bedroom temperature can influence nocturnal thermoregulation and sleep. To date, limited, small experimental studies have shown that bedroom temperatures outside the recommended range of 65 and 70°F can negatively impact sleep. However, this association has not been studied in a large-scale data set. Using over 3.75 million nights of objectively measured data, we analyzed the associations between habitual bedroom temperatures and sleep. Methods Over 3.75 million nights of sleep and bedroom temperature data were collected using S+ by ResMed technology from 34,096 Individuals (57% male, 20-90 years, mean age 48.7 +/-14.5 years, all US residents). Multilevel regression analyses were used to analyze associations between bedroom temperature and sleep. A stricter alpha level of 0.001 was used to account for the large number of observations in the dataset. Results Bedroom temperature was above 70°F for 69% of nights, with the average temperature ranging between 68.8 and 76.2°F. For each 1°F increase in bedroom temperature between 60-85°F, sleep efficiency decreased by 0.06%. Likewise, higher bedroom temperatures were linked to shorter Total Sleep Time duration (-0.45 mins/°F), longer Sleep Onset Latency (+0.04 mins/°F), and longer Wake After Sleep Onset (+0.11 mins/°F), all ps&amp;lt;0.001. Conclusion Analyzing data from over 3.75 million nights, we found that many people sleep in a bedroom warmer than the optimal temperature. Further, higher bedroom temperatures - even within the recommended range for optimal sleep - are associated with poorer sleep and higher wakefulness. Bedroom thermostats and cooling options should be considered to achieve optimal sleeping temperature conditions. Support N/A

Elevated airflow can maintain sleep quality and thermal comfort of the elderly in a hot environment.

The effect of elevated airflow on sleep quality was investigated with 18 elderly. Three airflow conditions were set: ceiling fan/30°C/max.0.8m/s and mean 0.7m/s, task fan/30°C/max.0.8m/s and mean 0.6m/s, and thermally neutral /27°C/0.2m/s. Sleep quality was evaluated objectively by analysis of electroencephalogram signals that were continuously monitored during the sleeping period. Urinary cortisol concentrations were analyzed to measure the activity of sympathetic nervous system. No significant difference in sleep quality, thermal comfort, or cortisol concentration was found between the ceiling fan and the neutral condition. The duration of total sleep time decreased by 35minutes, the duration of REM sleep decreased by 15minutes, and the cortisol concentration in the morning increased by 50ng/mL in the task fan than the other two conditions. Compared with ceiling fan, less heat load was removed in the task fan condition, possibly due to the lower air speed. This study shows that even small heat load led to reduced sleep quality and overactive sympathetic nervous system of the elderly. By supplying an airflow of 0.8m/s evenly over the human body, the elderly could maintain sleep quality and thermal comfort at an air temperature that was 3K higher than the neutral temperature.

Accuracy of Patient Perception of Supine Sleep.

For clinicians involved in investigating and treating sleep disorders, understanding the accuracy of patient recall of supine sleep would allow informed comparisons between polysomnography (PSG) and patient-reported sleep in patients with supine-predominant obstructive sleep apnea. This study aims to assess the accuracy of patient perception of supine sleep. Prospective observational cohort study, assessing patient perception of total sleep and supine sleep, including duration. Data were analyzed utilizing descriptive statistics, bias-plot (Bland-Altman) analysis, and Spearman correlation (rs) to analyze relationships among continuous data. Total number of patients who underwent PSG was 518, with data from 368 of these patients analyzed. Most of these patients underwent diagnostic PSG (49.2%). Patients were excluded because of missing or incomplete data (n = 133) or immobility (n = 17). Some patients (n = 97, 26%) did not perceive supine sleep, with 34 (35% of those with unperceived supine sleep or 9% of whole group) of these having more than 60 minutes of PSG supine sleep (range 0-305.5 minutes). All "unsure" patients (n = 8, 2.2%) had significant supine sleep recorded (31.5-257.5 minutes). For the presence of any PSG supine sleep, questioning had a sensitivity of 77.9%, specificity 72.7% with positive predictive value of 96.7% and negative predictive value of 24.5%. There was a significant correlation (rs = 0.63, P < .0001) between perceived and PSG supine sleep, but wide limits of agreement (-246.9 to 194.2 minutes). In patients undergoing in-laboratory PSG, the perception of supine sleep predicts the presence of PSG supine sleep. However, questioning patients has a poor negative predictive value and patient estimates of supine sleep duration are inaccurate.

Effect of nesting on sleep pattern among preterm infants admitted in NICU

Preterm infants are babies born before completion of 37 w of gestation. Their organs are immature especially brain. Sleep has a vital role in brain development and maturation in infants. Neonatal intensive care unit is a place where infant’s comfort is disturbed by many environmental stimuli. So the sleep is disrupted. Nesting facilitates transformation of sleep pattern from erratic disturbed spells to deep peaceful nights and contented days. This study aimed to investigate the effect of nesting on sleep pattern of infants hospitalized in NICUs. This crossover clinical trial was performed at a tertiary Neonatal Intensive Care Unit (NICU). 21 preterm infants who met the inclusion criteria were enrolled. They were randomly assigned to two groups of nest and routine procedure. Sleep status was evaluated by using neonatal sleep assessment Scale. Duration of Total Sleep Time per cycle (TST) and duration of each stage such as quiet sleep, active sleep indeterminate sleep were recorded and analysed by using paired t-test. Duration of Total Sleep Time per cycle (TST) and duration of each stage were significantly higher among preterm with nesting than usual procedure of care (p<0.001). Duration of sleep time in each stages shows, duration of active sleep is significantly reduced (34.76) with nesting as compared to routine care (39.55) although which is not significant (t=1.134, P=0.270) there is significant increase in quiet sleep (63.62 ± 17.957) with nesting than with routine care and indeterminate sleep time was increased with nesting as compared with sleep in routine care which is highly significant (t=4.570, p<0.001), (t=2.297, p=0.003) at 0.05 level of significance. The present study results supports the use of nesting aids in increase sleep and duration of quiet sleep and aids in stability of physiological parameters. Thus using nesting for preterm infant is recommended to facilitate infant’s quality of sleep in NICU.

Effects of acute sleep deprivation on motor and reversal learning in mice

Sleep supports the formation of a variety of declarative and non-declarative memories, and sleep deprivation often impairs these types of memories. In human subjects, natural sleep either during a nap or overnight leads to long-lasting improvements in visuomotor and fine motor tasks, but rodent models recapitulating these findings have been scarce. Here we present evidence that 5h of acute sleep deprivation impairs mouse skilled reach learning compared to a matched period of ad libitum sleep. In sleeping mice, the duration of total sleep time during the 5h of sleep opportunity or during the first bout of sleep did not correlate with ultimate gain in motor performance. In addition, we observed that reversal learning during the skilled reaching task was also affected by sleep deprivation. Consistent with this observation, 5h of sleep deprivation also impaired reversal learning in the water-based Y-maze. In conclusion, acute sleep deprivation negatively impacts subsequent motor and reversal learning and memory.

The relationship between sleep habits and academic performance in dental students in Croatia

It is well accepted that sleep and lifestyle habits affect academic success in students. However, sleep patterns and sleep problems amongst dental students have been insufficiently addressed in the literature. The purpose of this study was to evaluate sleep habits of dental students and the relationship between sleep habits and academic performance. A self-administered questionnaire on sleep habits, academic performance and lifestyle was administered. The participants were 447 dental students from Split University Dental Medicine School and Zagreb University Dental Medicine School from the six academic years. The subjects were classified into two groups based on academic success (high-performing vs. low-performing students) for comparison of sleep and lifestyle habits. Amongst the whole group of students, average bedtime and wake time during weekday was significantly earlier compared with weekend. Main findings indicate that students with high academic performance had earlier bedtimes during weekdays and weekends, earlier wake times during weekends and shorter sleep latency compared with low academic performing students. Self-reported academic performance of dental students in Croatia is associated with timing of sleep and wakefulness, rather than with total sleep time duration.

EEG Sleep Characteristics in Dysthymia and Major Depressive Disorder

All night EEG sleep recordings were compared in patients with dysthymia and major depressive disorder. Subjects were selected according to DSM-IV and underwent 2 weeks of treatment with placebo before the sleep evaluations. All patients with major depressive disorder were classified as nonmelancholic and belonged to the recurrent subtype, without full interepisode recovery. Patients with major depressive disorder have a shorter duration of total sleep time, a longer sleep latency and a lower sleep efficiency. However, similar sleep architecture and REM sleep characteristics were found in the two groups. These EEG sleep data seem to favor the existence of a biological overlap between the two forms of nonmelancholic unipolar depression. The validity of dysthymia is still unclear and therefore the nosological implications of our observations are discussed.

EEG sleep studies in patients with generalized anxiety disorder

Sleep polygraphic recordings were performed during 3 consecutive nights in 12 inpatients with generalized anxiety disorder (GAD) in comparison with age- and sex-matched groups of patients with major depressive disorder (MDD) and normal subjects. GAD patients differed significantly from those with MDD. A lower number of awakenings and stage shifts in night 1 and the mean of the 3 nights and a shorter rapid eye movement (REM) duration in night 1 but longer REM latency in the mean of the 3 nights were observed in GAD in comparison to MDD. GAD patients also showed a significantly longer sleep onset latency and shorter duration of total sleep time and Stage 2 than control subjects. Electroencephalographic sleep recordings, as well as other laboratory tests, may help the clinician to differentiate anxiety from depressive disorders.