Clinical trial NCT04223284: Olfactory Odour Stimulation for Metabolism Control
Official title: Olfactory Odour Stimulation for Metabolism Control - the "OLFAMET-Study"
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Keywords: D-limonene
lavender oil (SLVO)
Olfactory stimulation
Obesity
glucose metabolism
Lead sponsor: University Hospital, Basel, Switzerland
Sponsor class: OTHER
First posted: 2020-01-10
Enrollment: 41
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: OTHER

Brief summary: In this preliminary short-term study it is investigated, whether a short olfactory stimulation with D-Limonene leads to an acute improvement of glucose metabolism in patients with obesity.


Eligibility criteria: Inclusion Criteria:

* Age 18-70 years
* Obesity (BMI ≥35 kg/m2)
* Written informed consent
* Normosmia (defined by sniffin Sticks test)

Exclusion Criteria:

* Known allergy to D-Limonene, citrus fruits, citrus flavours, SLVO
* Regular smoking
* Current illicit drug abuse including daily marijuana and cannabidiol (CBD) consumption (alcohol ≤2 drinks per day allowed)
* Diabetes mellitus
* Pre-Treatment with insulin sensitizing drugs including GLP-1 analogues
* History of neurodegenerative diseases, severe head trauma
* Severe renal impairment (e.g. estimated glomerular filtration rate \<30 ml/min/m2)
* Known liver cirrhosis or other severe liver impairment
* Acute upper respiratory tract infection
* Uncontrolled dysthyroidism
* Uncontrolled hypertension
* Regular use of psychopharmaceutic drugs
* Patient aims to start a new diet or exercise program during the study
* Bariatric surgery
* Pregnancy/Lactation
* Symptoms of menopause
* Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc.
* Participation in an interventional study within the last 3 months

Primary outcomes:
measure: Change of area under blood glucose curve (AUBGC)
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections: 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
Secondary outcomes:
measure: AUBGC
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections: 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Visual Analogue Scale (VAS score)
timeFrame: Time Frame: baseline VAS score (timepoint 0) and VAS scores will be evaluated after 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma insulin levels
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections: 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma peak glucose levels
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections: 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of glucagon-like peptide 1 (GLP-1)
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of gastric inhibitory polypeptide (GIP)
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of Ghrelin
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of Leptin
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of Peptide YY (PYY)
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of Glucagon
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma Levels of Interleukin-6
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma Levels of C-reactive protein
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections after 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in plasma levels of lipids like LDL-cholesterine, total cholesterine, triglycerides
timeFrame: Time Frame: baseline blood exam (timepoint 0) and further blood collections: 5, 15, 30, 60, 90 and 120 minutes after drinking a standardized mixed-meal solution
measure: Change in heart rate
timeFrame: Blood pressure and heart rate will be measured at the following times: baseline (timepoint 0) and 30, 60, 120 minutes drinking a standardized mixed-meal solution
measure: Change in blood pressure
timeFrame: Blood pressure and heart rate will be measured at the following times: baseline (timepoint 0) and 30, 60, 120 minutes drinking a standardized mixed-meal solution
Other outcomes:
Locations:
city: Basel
country: Switzerland
facility: Clinic for Intensive Care Medicine, University Hospital Basel
Study officials:
affiliation: Endocrinology, Diabetology and Metabolism, University Hospital Basel
name: Katharina Timper, Dr. med
role: PRINCIPAL_INVESTIGATOR
References: