Shift-Work Sleep Disorder
Conditions
Keywords
shift work, melatonin, sleep
Brief summary
Nonstandard time-schedules work are widespread in the world of work. Shift and night work have been shown to be responsible for a desynchronization of biological rhythms, associated with melatonin secretion impairment and sleep disturbances. However, while health consequences of night and shift work are widely recognized and represent a major public health concern (High Authority of Health 2012 Recommendations and National Agency for Public Health Food, Environment and Work 2016 Report), the mechanisms by which the circadian system is affected by shift work remain poorly understood. Indeed most of the studies in the fields are cross-sectional, based on few blood or urinary samples in a single work position, in workers whose shift work patterns are often misidentified and heterogeneous. Moreover, few studies have assessed melatonin secretion alterations in relation to objective sleep measurement (actigraphy). The aim of this study is to assess the dynamics of melatonin secretion adaptation in 12-hour shift work and to correlate these data to sleep-wake cycle recording.
Interventions
OTHERmelatonin and cortisol sampling
The study will take place over 15 days during which the nurses will wear an actigraphic wristband and will fulfill a sleep log. During 3 periods of 24 hours selected during these 15 days, including a 12h day shift (Day 2), a 12h night shift (Day 8) and a rest (Day 13), the participants will collect their urine by 4 to 8 hour periods, note the corresponding urine volumes and for each period, sample a 5 mL tube which will be analyzed later (6-sulfatoxymelatonin and urinary cortisol assays). The subjects will complete questionnaires at the beginning of the study (Horne and Ostberg, Insomnia Severity Index, Epworth, Pichot, Hospital Anxiety and Depression) and the days corresponding to the urine sampling (Karolinska and St Mary Hospital).
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Nurses or nursing assistants working in the Sleep and Respiratory Diseases Department of the Croix-Rousse Hospital with positions in 12 hours for more than 6 months * informed consent given by the subject
Exclusion criteria
* Pregnancy or lactation \<6 months * Taking treatment modifying the secretion of melatonin (melatoninergic drugs (including antidepressants), beta-blockers) * Refusal of participate * Minor or major protected subject * Not affiliated to a social security scheme * Participant in another interventional study interfering with sleep / wake rhythm or work schedules (judgment of the investigator)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| total amount of melatonin excreted during the sleep period for the night shift | at day 8 (night shift) | The impact of 12H shift work on melatonin secretion dynamics will be assessed by comparing the total amount of melatonin excreted during the sleep period between the 12h day shift condition and the 12h night shift condition |
| total amount of melatonin excreted during the sleep period for the day shift. | at day 2 (day shift) | The impact of 12H shift work on melatonin secretion dynamics will be assessed by comparing the total amount of melatonin excreted during the sleep period between the 12h day shift condition and the 12h night shift condition |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Melatonin secretion dynamics in 12h night shift | at day 8 (night shift) | Secretion of melatonin on sequential urinary specimens collected every 4 or 8 hours. Measure of total excretion (ng) |
| Melatonin secretion dynamics at rest | at day 13 (rest) | Secretion of melatonin on sequential urinary specimens collected every 4 or 8 hours. Measure of total excretion (ng) |
| Cortisol secretion dynamics in 12h day shift | at day 2 (day shift) | Secretion of cortisol on sequential urinary specimens collected every 4 or 8 hours. Measure of total excretion (ng) |
| Cortisol secretion dynamics in 12h night shift | at day 8 (night shift) | Secretion of cortisol on sequential urinary specimens collected every 4 or 8 hours. Measure of total excretion (ng) |
| Cortisol secretion dynamics at rest | at day 13 (rest) | Secretion of cortisol on sequential urinary specimens collected every 4 or 8 hours. Measure of total excretion (ng) |
| Objective sleep quality | 15 days | Measure of sleep latency assessed by sleep log |
| Objective sleep duration | 15 days | duration of sleep assessed by actigraphy |
| Excessive daytime sleepiness | at day 1 | This outcome will be assessed by the Epworth sleepiness Scale |
| Total amount of melatonin excreted during the sleep period at rest | at day 13 (rest) | the total amount of melatonin excreted during the sleep period at rest will be compared to the total amount of melatonin excreted during the sleep period for the 12h day shift condition ant to the total amount of melatonin excreted during the sleep period for the 12h night shift condition |
| Insomnia severity | at day 1 | This outcome will be assessed by the Insomnia Severity Index |
| Anxiety | at day 1 | This outcome will be assessed by the Hospital Anxiety and Depression scale |
| Depression | at day 1 | This outcome will be assessed by the Hospital Anxiety and Depression scale |
| Vigilance at awakening | at day 2, 8 and 13 | This outcome will be assessed by the Karolinska scale |
| Sleep subjective quality | at day 2, 8 and 13 | This outcome will be assessed by the St Mary Hospital Questionary |
| Chronotype | at day 1 | This outcome will be assessed by the Horne and Ostberg Questionary |
| Light exposition | 15 days | This outcome will be assessed by the actigraphy |
| Asthenia | at day 1 | This outcome will be assessed by the Pichot asthenia scale |
| Melatonin secretion dynamics in 12h day shift | at day 2 (day shift) | Secretion of melatonin on sequential urinary specimens collected every 4 or 8 hours. Measure of total excretion (ng) |
Countries
France
Outcome results
None listed