Shift work sleep disorder: Prevalence and consequences beyond that of symptomatic day workers
ABSTRACT Although there are considerable data demonstrating the impact of shift work on sleep and alertness, little research has examined the prevalence and consequences of shift work sleep disorder in comparison to the difficulties with insomnia and excessive sleepiness experienced by day workers. The present study was designed to determine the relative prevalence and negative consequences associated with shift work sleep disorder in a representative sample drawn from the working population of metropolitan Detroit.
Random-digit dialing techniques were used to assess individuals regarding their current work schedules and a variety of sleep- and non-sleep-related outcomes.
Detroit tricounty population.
A total of 2,570 individuals aged 18 to 65 years from a representative community-based sample including 360 people working rotating shifts, 174 people working nights, and 2036 working days.
Using standardized techniques, individuals were assessed for the presence of insomnia and excessive sleepiness, based on DSM-IV and ICSD criteria. Those individuals with either insomnia or excessive sleepiness and who were currently working rotating or night schedules were classified as having shift work sleep disorder. Occupational, behavioral, and health-related outcomes were also measured. Individuals who met criteria for shift work sleep disorder had significantly higher rates of ulcers (odds ratio = 4.18, 95% confidence interval = 2.00-8.72), sleepiness-related accidents, absenteeism, depression, and missed family and social activities more frequently compared to those shift workers who did not meet criteria (P < .05). Importantly, in most cases, the morbidity associated with shift work sleep disorder was significantly greater than that experienced by day workers with identical symptoms.
These findings suggest that individuals with shift work sleep disorder are at risk for significant behavioral and health-related morbidity associated with their sleep-wake symptomatology. Further, it suggests that the prevalence of shift work sleep disorder is approximately 10% of the night and rotating shift work population.
Full-textDOI: · Available from: James K Walsh, Jul 20, 2015
- SourceAvailable from: Christopher Drake
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- "In addition to the possibility that PER3 genotype may impact nocturnal alertness in night-shift workers, previous studies demonstrating an association of this polymorphism with chronotype (Archer et al., 2003) and circadian phase (Viola et al., 2012) suggest these genotype differences may also influence circadian adjustment to night work. Numerous studies have shown that certain individuals adjust better to night work than others (Drake et al., 2004; Gumenyuk et al., 2012, 2014; Juda et al., 2013; Reinberg et al., 1978). In a review of six studies, Folkard concluded that few night workers experience full adjustment of their circadian rhythms to night work (Folkard, 2008). "
ABSTRACT: The objective of the current study was to determine if night-shift workers carrying the five-repeat variant of the Period 3 gene show elevated levels of nocturnal sleepiness and earlier circadian phase compared with homozygotes for the four-repeat allele. Twenty-four permanent night-shift workers were randomly selected from a larger study. Participants took part in an observational laboratory protocol including an overnight multiple sleep latency test and half-hourly saliva collection for calculation of dim-light melatonin onset. Period 3(-/5) shift workers had significantly lower multiple sleep latency test during overnight work hours compared with Period 3(4/4) workers (3.52 ± 23.44 min versus 10.39 ± 6.41 min, P = 0.003). We observed no significant difference in sleepiness during early morning hours following acute sleep deprivation. Long-allele carriers indicated significantly higher sleepiness on the Epworth Sleepiness Scale administered at 17:00 hours (12.08 ± 2.55 versus 8.00 ± 1.94, P < 0.001). We observed a significantly earlier melatonin onset in Period 3(-/5) individuals compared with Period 3(4/4) shift workers (20:44 ± 6:37 versus 02:46 ± 4:58, P = 0.021). Regression analysis suggests that Period 3 genotype independently predicts sleepiness even after controlling for variations in circadian phase, but we were unable to link Period 3 to circadian phase when controlling for sleepiness. Period 3(-/5) shift workers showed both subjective and objective sleepiness in the pathological range, while their Period 3(4/4) counterparts showed sleepiness within normal limits. Period 3(-/5) night workers also show a mean circadian phase 6 h earlier (i.e. less adapted) than Period 3(4/4) workers. Because Period 3(-/5) workers have maladaptive circadian phase as well as pathological levels of sleepiness, they may be at greater risk for occupational and automotive accidents. We interpret these findings as a call for future research on the role of Period 3 in sleepiness and circadian phase, especially as they relate to night work. © 2014 European Sleep Research Society.Journal of Sleep Research 12/2014; 24(3). DOI:10.1111/jsr.12264 · 2.95 Impact Factor
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- "Although the mechanisms by which LAN exposure may increase nighttime BP remain unclear, previous epidemiological and experimental studies support a negative effect of LAN exposure on nighttime BP by changing in endogenous melatonin levels, sleep quality and/or patterns of sympathetic nerve activity. Decreased endogenous melatonin levels and impaired sleep quality are observed in night-shift workers (Drake et al., 2004; Grundy et al., 2011), and night-shift workers have higher nighttime BP (Chau et al., 1989; Lo et al., 2008; Yamasaki et al., 1998). "
ABSTRACT: Circadian misalignment between internal and environmental rhythms dysregulates blood pressure (BP) variability because of disruption of the biological clock, resulting in increased nighttime BP. Although exposure to light-at-night is associated with the circadian misalignment, it remains unclear whether exposure to light-at-night in home settings is associated with nighttime BP. In this cross-sectional analysis of 528 elderly individuals (mean age: 72.8 years), we measured bedroom light intensity at 1-min intervals on two consecutive nights along with ambulatory BP, overnight urinary melatonin excretion and actigraphy. With regard to adjusted mean comparisons using analysis of covariance, the light-at-night group (average: ≥5 lux; n = 109) showed significantly higher nighttime systolic BP (SBP; adjusted mean: 120.8 vs. 116.5 mmHg, p = 0.01) and diastolic BP (70.1 vs. 67.1 mmHg, p < 0.01) compared with the Darker group (average: <5 lux; n = 419) independently of potential confounding factors including overnight urinary melatonin excretion and actigraphic sleep quality. We observed consistent associations between light-at-night and nighttime BP in different cutoff values for light-at-night intensity (i.e. 3 and 10 lux). In conclusion, exposure to light-at-night in home settings is significantly associated with increased nighttime BP in elderly individuals independently of overnight urinary melatonin excretion. A 4.3 mmHg increase in nighttime SBP is associated with a 6.1% increase in total mortality, which corresponds to approximately 10 000 annual excess deaths in Japanese elderly population.Chronobiology International 03/2014; DOI:10.3109/07420528.2014.900501 · 2.88 Impact Factor
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- "They are not spiteful when awaking and are more tired along the day. This is due to discrepancy between circadian rhythm and sleeping and awaking time in these populations  . "
ABSTRACT: The consequences of sleep deprivation and sleepiness have been noted as the most important health problem in our modern society among shift workers. The objective of this study was to investigate the prevalence of sleep disorders and their possible effects on work performance in two groups of Iranian shift workers and nonshift workers. This study was designed as a cross-sectional study. The data were collected by PSQI, Berlin questionnaire, Epworth Sleepiness Scale, Insomnia Severity Index, and RLS Questionnaire. Occupational impact of different sleep disorders was detected by Occupational Impact of Sleep Disorder questionnaire. These questionnaires were filled in by 210 shift workers and 204 nonshift workers. There was no significant difference in the age, BMI, marital status, and years of employment in the two groups. Shift workers scored significantly higher in the OISD. The prevalence of insomnia, poor sleep quality, and daytime sleepiness was significantly higher in shift workers. Correlations between OISD scores and insomnia, sleep quality, and daytime sleepiness were significant. We concluded that sleep disorders should receive more attention as a robust indicator of work limitation.05/2014; 2014:870320. DOI:10.1155/2014/870320