Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04302922 |
Other study ID # |
BU 1807/3-2 |
Secondary ID |
|
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
September 1, 2019 |
Est. completion date |
February 28, 2023 |
Study information
Verified date |
April 2024 |
Source |
Paderborn University |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
Chronotype is defined as the midpoint of sleep and describes a biological construct of an
organism's temporal organisation. Misalignment between the individual chronotype and socially
determined schedules may result in a phenomenon called "social jetlag". Emerging evidence
indicates that both, a later chronotype and/or a substantial "social jetlag" adversely
affects metabolic health. Young adults may be particularly vulnerable to these exposures
since the chronotype progressively delays from adolescence until early adulthood (approx. 20
years of age) before it advances again. Simultaneously, education in institutions or working
hours starts early during the day, potentially contribute to substantial "social jetlag".
Data on the development of overweight / obesity prevalence in Germany indicates that rates
are now constant or declining in most adult age groups, with the clear exception of young
adults, in whom rates continue to be on the rise. Nonetheless, the potential contribution of
chronotype and/or social jetlag to this secular trend has not been addressed in Germany.
Hence, the hypothesis of the ChroNu cohort is that individual chronotype and social jetlag
are predictors of (changes in) the body composition in young adulthood (ages 18-25 years) and
that changes in chronotype / social jetlag will result in changes in body composition. The
ChroNu cohort forms part of the overall ChroNu study, which addresses the hypothesis that
timing of food intake which diverges from the individual chronotype constitutes a
characteristic of social jetlag which has adverse short- and long-term consequences for
metabolic health (see The ChroNustudy). This study will recruit 300 healthy, non-obese
students aged 18-25 years enrolled at Paderborn University until February 2020 and follow
these up one year later. Chronotype and social jetlag will be determined using the validated
MCTQ. Body composition will be assessed by bioimpedance analysis (BIA) The ChroNu cohort
study will reveal important information on the relevance of a biologically determined
phenomenon, i.e. the chronotype and the potentially resultant social jetlag for body
composition development in a population vulnerable to increases in body fat.
Description:
Background:
The chronotype is defined as the midpoint of sleep and describes biological construct of an
organisms temporal organisation. It is itself determined by genetics, age, sex, and
environment. Misalignment between the individual chronotype and socially determined schedules
may result in a phenomenon which has been called "social jetlag". Emerging evidence indicates
that a later chronotype and/or "social jetlag" predisposes to weight gain, higher BMI and
higher odds for type 2 diabetes. A later chronotype has been also associated with a more
adverse body composition. Since the chronotype progressively delays from adolescence until
early adulthood (approx. 20 years of age), before it advances again, young adults may be
particularly vulnerable to such adverse exposures. These exposures may result of a higher
evening energy intake which in turn was observed for a later chronotype at adolescence. A
preferred consumption of energy intake in the evening lead to higher total energy intake.
Social schedules such as early starting hours at schools and universities, which potentially
contribute to substantial "social jetlag", may influence individual meal timing. The
chronotype, however, may be the main predictor for meal timing like skipping breakfast or
not. However, it is not clear yet whether this affects predominantly early or late
chronotypes in young adults.
Data on the development of overweight / obesity prevalence in Germany indicates that rates
are now constant or declining in most adult age groups, with the clear exception of young
adults, in whom rates continue to be on the rise. Nonetheless, the potential contribution of
chronotype and/or social jetlag to this secular trend has not been addressed in Germany.
Hypothesis:
The hypothesis of the ChroNu cohort is that individual chronotype and social jetlag are
predictors of (changes in) body composition in young adulthood (ages 18-25 years) and that
changes in chronotype / social jetlag will result in changes in body composition.
Aim:
Hence, the investigators aim to study the association between the body composition and the
chronotype / social jetlag at first stage and in a follow-up after one year the causal
relationship between changes in chronotype/social jetlag and body composition.
Methods 1: participants In the ChroNu cohort study, the investigators will recruit at least
300 students from Paderborn University aged 18 -25 years. Students will be contacted via
social media, mailing-lists, poster and flyer, and presentation of the study in lectures. The
ChroNu cohort study will last from Sept 2019 to approximately Febr 2020. Due to the
restrictions caused by the SARS-CoV2 pandemic, participants were recruited again in June 2020
to fill in an online survey consisting of the same questionairies as at baselineThe follow-up
is scheduled for May - June 2022.
Methods 2: Methods:
In the screening of participants for ChroNu cohort study, eligible participants are asked to
fill in the Munich Chronotype Questionnaire (MCTQ, © Roenneberg & co-workers 2015), which is
a validated questionnaire to calculate the individual chronotype. In this questionnaire,
participants are asked about their sleep timing separately for work days and work-free days:
when they go to bed (bed time); when they prepare to sleep); how long it takes them to fall
asleep (sleep latency); when they wake up (sleep end); and how long it takes them to get out
of bed (sleep inertia). The mid-sleep point, which defines the chronotype, is calculated as
the time when falling asleep plus half of the sleep duration. If the sleep duration is longer
on free days than on work days this oversleep is corrected (corrected mid-sleep point): half
of the difference in sleep duration is subtracted. Social jet lag is calculated as the
difference between the mid-sleep time on work days and work-free days.
The individual body composition, which is the outcome of this study, is analyzed using
Bioimpedance Analysis (BIA) (mBCA 515, SECA). For the analyses, waist circumference, body
size and body weight are required: waist circumference is measured midway between the lowest
rib and the iliac crest by trained personal following the World Health Organisation (WHO)
recommendations and entered in the BIA device. Body size is measured by means of an
ultrasonic measuring station (seca 287 dp) from SECA and directly transferred to the BIA
device. For measurement of body weight and body composition participants need to stand on the
BIA device.
Since the chronotype and potentially resultant social jetlag is affected by environment,
participants are asked to fill in additional questionnaires on their daily routines and
diurnal patterns in both physical activity and meal timing and food intake. Questions on
daily routine include start and end time of both university and work if applicable.
For a following ChroNu nutritional trial, the investigators are looking for the earliest and
latest chronotypes among our ChoNu cohort. Participants each with the earliest and the latest
mid-sleep points among our cohort seem to be suitable.
Statistical analyses Linear mixed-effects regression models are used to analyze the
associations between chronotype (continuously in h:mm) as predictor and BMI, body fat, and
visceral fat. The same analyses will be performed for social jetlag as predictor.
Multivariable linear and logistic mixed-effects regression models are performed to
investigate associations between the chronotype and the circadian patterns of meal timing and
physical activity. In second step, multivariable regression analysis is used to examine if
the assocation between chronotype and body composition is mediated by the circadian patterns
of both meal timing and physical activity. All basic models will be adjusted for age and
additionally adjusted for potentially confounders which were considered as statistically
significant.