The Daytime Circadian Rhythm in Exhaled Volatile Organic Compounds in People Living Without and Diabetes

NCT05984979 | Recruiting

• 1 other identifier: VOCircle
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

Exhaled volatile organic compounds will be measured during daytime with the goal to identifying circadian variability. The study incudes three subgroups: people without diabetes, people with type 1 diabetes, and people with type 2 diabetes. A total of 60 people will be recruited for the study.

Conditions

Diabetes Mellitus

Outcome Measures

Primary Outcomes (2)

• VOC Patterns over time as gallery plots

  Gallery plots (3D visualization of retention index, drift time, ion current) from selected VOC peaks over time.

  During the study procedure (approximately 8 hours)

• VOC Patterns over time as boxplots

  Box plots from selected VOC peaks over time.

  During the study procedure (approximately 8 hours)

Secondary Outcomes (4)

• Capillary blood glucose

  During the study procedure (approximately 8 hours)

• Correlation between VOCs in breath intestinal microbiota

  day 1

• Correlation between VOCs in breath oral microbiota

  day 1

• Correlation between VOCs and subgroups

  day 1 or 8 hours

Study Arms (3)

People without diabetes

Other: Standardized meal

People with type 1 diabetes

Other: Standardized meal

People with type 2 diabetes

Other: Standardized meal

Interventions

Standardized meal OTHER

The participants will receive a standardized meal for breakfast

People with type 1 diabetes; People with type 2 diabetes; People without diabetes

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

60 participants with the following subgroups: Subgroup 1: People without diabetes Subgroup 2: People diagnosed with T1D Subgroup 3: People diagnosed with T2D

You may qualify if:

• Subgroup 1:
• Age 18 or older
• HbA1c below 6.5%
• Written informed consent
• Subgroup 2:
• Age 18 or older
• T1D (Type 1 diabetes) with MDI (multiple daily injection) or CSII (Continuous subcutaneous insulin infusion therapy) therapy \>1 year
• Written informed consent
• Subgroup 3
• Age 18 or older
• T2D (Type 2 diabetes) with oral antidiabetic medication or insulin therapy
• Written informed consent

You may not qualify if:

• Pregnancy or breastfeeding
• Smoking (last cigarette less than 6 months ago)
• Any chronical lung and intestinal disease diagnosis (such as intestinal bowel disease (IBD); asthma; COPD (chronic obstructive pulmonary disease); lung cancer, …)
• Coeliac disease
• Lactose and fructose intolerance
• Any acute disease diagnosis (such as viral or bacterial infection)
• Drinking habit of more than four units of alcohol per day
• Current inhaled medicines treatments
• Antibiotic treatment in the previous 4 months

Sponsors & Collaborators

• DCB Research AG: collaborator
• University of Bern: lead
• Insel Gruppe AG, University Hospital Bern: collaborator

Study Sites (1)

University of Bern

Bern, 3010, Switzerland

RECRUITING

Biospecimen

Retention: SAMPLES WITHOUT DNA

The spare aliquots used for the study research will be destroyed after the completion of the study. Purified oral and gut microbiota DNA will be stored up to 10 years.

MeSH Terms

Conditions

Diabetes Mellitus

Condition Hierarchy (Ancestors)

Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases

Study Officials

• Lilian Witthauer, Prof.Dr.

  University of Bern

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lilian Witthauer

CONTACT

+41 31 664 22 77; lilian.witthauer@unibe.ch

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: OTHER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 24, 2023
• First Posted: August 9, 2023
• Study Start: August 7, 2023
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026
• Last Updated: December 8, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

CH (1)