The Daytime Circadian Rhythm in Exhaled Volatile Organic Compounds in People Living Without and Diabetes
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Standardized meal.
- Who it may be relevant to
- Registry conditions: Diabetes Mellitus. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Switzerland
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
The Daytime Circadian Rhythm in Exhaled Volatile Organic Compounds in People Living Without and With Type 1 and 2 Diabetes: an Exploratory Study
Overview
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.
Interventions
- Other Standardized meal
The participants will receive a standardized meal for breakfast
Primary outcome measures
- VOC Patterns over time as gallery plots [Time frame: During the study procedure (approximately 8 hours)]
- VOC Patterns over time as boxplots [Time frame: During the study procedure (approximately 8 hours)]
Secondary outcome measures (4)
- Capillary blood glucose [Time frame: During the study procedure (approximately 8 hours)]
- Correlation between VOCs in breath intestinal microbiota [Time frame: day 1]
- Correlation between VOCs in breath oral microbiota [Time frame: day 1]
- Correlation between VOCs and subgroups [Time frame: day 1 or 8 hours]
Eligibility criteria
Inclusion criteria
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
Exclusion criteria
- 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Other
Study locations
Switzerland · 1 center
- University of Bern — Bern
Publications
- Nicolier C, Rothenbuhler M, Balmer ML, Witthauer L. Daytime circadian patterns of exhaled volatile organic compounds in adults without and with type 1 and type 2 diabetes: protocol for an exploratory observational study. BMJ Open. 2026 Apr 8;16(4):e113892. doi: 10.1136/bmjopen-2025-113892. PMID 41951262
Identifiers
NCT: NCT05984979 · VOCircle