The aim of the study is to evaluate circadian glucose, activity and dietary rhythms, as well as metabolic and cardiovascular risk associated with night shift work, sleep quality and well-being in a cohort of hospital staff, comparing employees with night shifts to employees without night shifts.
The parallel-arm study consists of group A of employees working night shifts and group B of employees not working night shifts. After a pre-screening and an inclusion examination, both groups attend their first visit after at least two day shifts before the start of their two-week observation phase. During the visit, anthropometric measurements are conducted, blood and hair samples are collected, and questionnaires are completed and handed out. During the observation period, the 24-hour activity and glucose rhythms of the study participants are measured and the food intake is documented. After an observation phase, group A attends a second visit after at least two night shifts, including blood and hair sample collection.
Study Type
OBSERVATIONAL
Enrollment
48
Charité-Universitaetsmedizin Berlin, Department of Anesthesiology and Intensive Care Medicine (CCM/CVK)
Berlin, Germany
Mean 24-hour glucose levels and mean night glucose levels
Mean 24-hour glucose \[mg/dl\] and mean night glucose \[mg/dl\] assessed by continuous glucose monitoring (CGM)
Time frame: 2 weeks
Body weight
Body weight \[kg\], as measured by scale weight
Time frame: 2 weeks
Body Mass Index (BMI)
BMI \[kg/m2\], calculated as weight/square height
Time frame: 2 weeks
Blood pressure
Systolic and diastolic blood pressure \[mm Hg\], as measured by manometer
Time frame: 2 weeks
Glycemic variability
Inter- and intraday indices of glycemic variability assessed by CGM
Time frame: 2 weeks
Eating time
Timing of all eating events \[hh:mm\] as assessed by food records
Time frame: 2 weeks
Calorie intake
Calorie intake \[kcal\] as assessed by food records
Time frame: 2 weeks
Food composition
Nutrient composition \[EN%\] as assessed by food records
Time frame: 2 weeks
Subjective sleep quality
Sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI score, which ranges from 0-21, where higher values correspond to worse sleep quality)
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Time frame: 2 weeks
Objective sleep quality
Sleep quality as assessed by the ActLumus device
Time frame: 14 days
Sleep timing
Sleep timing (sleep onset and offset \[hh:mm\]) as monitored using a sleep diary
Time frame: 14 days (sleep diary)
Body temperature
Body temperature is monitored continuously across the entire 24-hour cycle for two weeks by an ActLumus device
Time frame: 2 weeks
Light exposure
Light exposure is monitored continuously across the entire 24-hour cycle for two weeks by an ActLumus device
Time frame: 2 weeks
Physical activity
Physical activity is monitored continuously across the entire 24-hour cycle for two weeks by an ActLumus device
Time frame: 2 weeks
Concentration of liver enzymes
γ-glutamyltransferase (GGT), aspartate aminotransferase (ALT) and alanine aminotransferase (AST) assessed in blood plasma
Time frame: 2 weeks
Concentration of lipids
Total cholesterol, high-density lipoprotein and low-density lipoprotein cholesterol and triglycerides assessed in blood plasma
Time frame: 2 weeks
Concentration of kidney parameters
Creatinine, urea and uric acid assessed in fasting blood samples
Time frame: 2 weeks
Glucose concentration
Glucose levels \[mg/dl\] assessed in fasting blood samples
Time frame: 2 weeks
HbA1C concentration
HbA1C \[%\] assessed in blood samples
Time frame: 2 weeks
Insulin concentration
Levels of insulin assessed using ELISA in serum samples
Time frame: 2 weeks
Cortisol concentration
Levels of cortisol assessed in blood serum
Time frame: 2 weeks
Thyroid-stimulating hormone (TSH) concentration
Levels of TSH assessed in blood serum
Time frame: 2 weeks
Leptin concentration
Levels of leptin assessed in blood serum
Time frame: 2 weeks
Concentration of C-reactive protein (CRP)
CRP assessed in blood serum
Time frame: 2 weeks
Concentration of interleukin-6 (IL-6)
IL-6 assessed in blood serum
Time frame: 2 weeks
Gene expression in blood cells
Whole blood transcriptome assessed by RNAseq
Time frame: 2 weeks
Internal circadian phase
Circadian phase as assessed using the HairTime assay in hair samples
Time frame: 2 weeks
Chronotype
Chronotype will be determined using the Munich ChronoType Questionnaire (MCTQ) , with scores ranging from 16 to 86. Lower scores indicate extreme late chronotypes, while higher scores indicate extreme early chronotypes
Time frame: 2 weeks