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Biological Rhythms Impact of 12 Hours Shift Work

Not Applicable
Completed
Conditions
Shift-Work Sleep Disorder
Interventions
Other: melatonin and cortisol sampling
Registration Number
NCT03153917
Lead Sponsor
Hospices Civils de Lyon
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.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
15
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
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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)
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Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
melatonin and cortisol samplingmelatonin and cortisol sampling14 healthy volunteer nurses working on 12 hours night/day schedules in the Sleep Medicine Center of Lyon.
Primary Outcome Measures
NameTimeMethod
total amount of melatonin excreted during the sleep period for the night shiftat 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 Outcome Measures
NameTimeMethod
Melatonin secretion dynamics in 12h day shiftat day 2 (day shift)

Secretion of melatonin on sequential urinary specimens collected every 4 or 8 hours.

Measure of mesor (ng)

Objective sleep quality15 days

Measure of intra-sleep wakefulness assessed by actigraphy

Insomnia severityat day 1

This outcome will be assessed by the Insomnia Severity Index

Chronotypeat day 1

This outcome will be assessed by the Horne and Ostberg Questionary

Melatonin secretion dynamics in 12h night shiftat day 8 (night shift)

Secretion of melatonin on sequential urinary specimens collected every 4 or 8 hours.

Measure of mesor (ng)

Sleep subjective qualityat day 2, 8 and 13

This outcome will be assessed by the St Mary Hospital Questionary

Light exposition15 days

This outcome will be assessed by the actigraphy

Total amount of melatonin excreted during the sleep period at restat 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

Melatonin secretion dynamics at restat day 13 (rest)

Secretion of melatonin on sequential urinary specimens collected every 4 or 8 hours.

Measure of mesor (ng)

Cortisol secretion dynamics in 12h day shiftat day 2 (day shift)

Secretion of cortisol on sequential urinary specimens collected every 4 or 8 hours.

Measure of mesor (ng)

Cortisol secretion dynamics in 12h night shiftat day 8 (night shift)

Secretion of cortisol on sequential urinary specimens collected every 4 or 8 hours.

Measure of mesor (ng)

Cortisol secretion dynamics at restat day 13 (rest)

Secretion of cortisol on sequential urinary specimens collected every 4 or 8 hours.

Measure of mesor (ng)

Astheniaat day 1

This outcome will be assessed by the Pichot asthenia scale

Objective sleep duration15 days

duration of sleep assessed by actigraphy

Excessive daytime sleepinessat day 1

This outcome will be assessed by the Epworth sleepiness Scale

Anxietyat day 1

This outcome will be assessed by the Hospital Anxiety and Depression scale

Depressionat day 1

This outcome will be assessed by the Hospital Anxiety and Depression scale

Vigilance at awakeningat day 2, 8 and 13

This outcome will be assessed by the Karolinska scale

Trial Locations

Locations (1)

Croix-Rousse Hospital

🇫🇷

Lyon, France

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