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

Study Overview
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Brief Summary
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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.

Official Title
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The Daytime Circadian Rhythm in Exhaled Volatile Organic Compounds in People Living Without and With Type 1 and 2 Diabetes: an Exploratory Study

Conditions
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Diabetes Mellitus

Intervention / Treatment
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* Other: Standardized meal


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| People without diabetes<br> | Other: Standardized meal<br>* The participants will receive a standardized meal for breakfast<br>|
| People with type 1 diabetes<br> | Other: Standardized meal<br>* The participants will receive a standardized meal for breakfast<br>|
| People with type 2 diabetes<br> | Other: Standardized meal<br>* The participants will receive a standardized meal for breakfast<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Capillary blood glucose | Correlation between capillary blood glucose and VOCs | During the study procedure (approximately 8 hours) | 
| Correlation between VOCs in breath intestinal microbiota | Correlation between VOCs in breath and intestinal microbiota species abundance | day 1 | 
| Correlation between VOCs in breath oral microbiota | Correlation between VOCs in breath and oral microbiota species abundance | day 1 | 
| Correlation between VOCs and subgroups | Wilcoxon signed-rank test will be used to explore if the patterns in VOCs differ between subgroup: people without diabetes, people living with T1D, and people living with T2D | day 1 or 8 hours |