NCT06288568

Brief Summary

Shift work is a well-known risk factor for the development of overweight and obesity, which may lead to downstream effects such as increased risk of cardiometabolic diseases and cancer. However, the biological and behavioral mechanisms underlying the obesogenicity of night shift work are not well understood. Population-based mechanistic studies in real life shift workers are needed to address how night shift work impacts metabolic health. The investigators aim to characterize the behavioural, environmental, and biological mechanisms and pathways for the association of night shift work and obesity across Europe. The investigators will conduct a cross sectional study in 5 European countries (Austria, Denmark, Germany, Netherlands and Poland) and recruit 1000 rotating night shift workers and day workers (200/country) from the health sector and different industries. Night and day workers will be age-frequency (3 age groups), gender and (where possible) working tasks matched. Participants will complete online questionnaires and report their diet habits in a mobile app. Body composition, dietary behavior and sensory preferences will be tested. Biologic specimens (blood, urine, saliva, hair and feces) will be collected at the workplace on a day where participants are working on a day shift (or a day off). In a subsample (Austria and Netherlands) shift workers will provide biological samples (spot blood, urine and saliva) both on a day shift and on a night shift. Biomarkers including hormones, cellular immunity and inflammation, parameters linked to gut health and metabolism of fat and sugar, appetite, oxidative stress, metabolomics and microbiota will be measured. The investigators hypothesize that compared to day workers, night shift workers will experience disrupted levels of pre-obesity markers. Higher circadian disruption, sleep disruption and mistimed eating patterns workers will be associated with more disrupted biomarker profiles. Among rotating shift workers, night shift will be associated with acute disrupted melatonin production, metabolomic profiles and composition of oral microbiota compared to a day shift.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
1,000

participants targeted

Target at P75+ for all trials

Timeline
25mo left

Started Apr 2024

Longer than P75 for all trials

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress50%
Apr 2024May 2028

First Submitted

Initial submission to the registry

February 23, 2024

Completed
7 days until next milestone

First Posted

Study publicly available on registry

March 1, 2024

Completed
1 month until next milestone

Study Start

First participant enrolled

April 1, 2024

Completed
1.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 1, 2025

Completed
2.6 years until next milestone

Study Completion

Last participant's last visit for all outcomes

May 31, 2028

Expected
Last Updated

September 8, 2025

Status Verified

February 1, 2025

Enrollment Period

1.6 years

First QC Date

February 23, 2024

Last Update Submit

September 5, 2025

Conditions

Outcome Measures

Primary Outcomes (1)

  • high-sensitive C-Reactive Protein (hs-CRP)

    Compare hs-CRP levels between night shift workers and day shift workers

    Baseline

Secondary Outcomes (23)

  • The investigators will consider levels of hormones in plasma

    Baseline

  • The investigators will consider levels of hormones in plasma

    Baseline

  • The investigators will consider levels of parameters linked to gut health in serum and in feces

    Baseline

  • The investigators will consider levels of parameters linked to gut health in serum and in feces

    Baseline

  • The investigators will consider levels of parameters linked to gut health in serum and in feces

    Baseline

  • +18 more secondary outcomes

Study Arms (2)

Nightshift workers

Nightshift worker in the health care and industrial sector. Night shift is defined as a work schedule that involves working at least 3 hours between 00:00 and 5:00, at least 2 consecutive nights/month.

Other: No intervention

Dayshift workers

Dayshift worker in the health care and industrial sector. No night shifts.

Other: No intervention

Interventions

No intervention

Dayshift workersNightshift workers

Eligibility Criteria

Age21 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

We are recruiting shift worker and day worker in the industrial and healthcare setting.

You may qualify if:

  • Health care sector or industrial shift worker
  • Employed or self-employed
  • years or older
  • ≥ 24 h/ week
  • Shift work duration \> 3 years and currently doing night shifts
  • or more rotating night shifts/month (night shift defined as a work schedule that involves working at least 3 hours between 00:00 and 5:00), at least 2 consecutive nights/month
  • Health care sector or industrial work
  • Employed or self-employed
  • years or older
  • ≥ 24 h/ week
  • No night shift or rotating shift work in the last 5 years
  • No history of night shift or rotating shift work for more than 5 years

You may not qualify if:

  • Pregnancy
  • Lactation period
  • BMI of 40 kg/m2 or above
  • Present treatment of a disease e.g. cancer radio- or chemotherapy
  • Chronic diseases if in an ongoing therapy but not after a remission (renal failure, active hepatitis, cirrhosis, myocardial infarction, chronic obstructive pulmonary disease and cancer)
  • Immunodeficiency syndrome, any auto-immune or auto-inflammatory diseases (e.g. type-1 diabetes, multiple sclerosis, lupus, rheumatoid arthritis) and acute episodes of atopic diseases (atopic dermatitis, asthma, type 1 allergies such as hay fever)
  • Bariatric surgery
  • Antibiotics in the last month

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Medical University of Vienna

Vienna, Vienna, 1090, Austria

RECRUITING

MeSH Terms

Conditions

ObesityChronobiology Disorders

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and SymptomsNervous System Diseases

Study Design

Study Type
observational
Observational Model
CASE CONTROL
Time Perspective
CROSS SECTIONAL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

February 23, 2024

First Posted

March 1, 2024

Study Start

April 1, 2024

Primary Completion

November 1, 2025

Study Completion (Estimated)

May 31, 2028

Last Updated

September 8, 2025

Record last verified: 2025-02

Locations