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Completed

NCT Number: NCT04223284

Olfactory Odour Stimulation for Metabolism Control

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.

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Key information

Conditions

Obesity Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Clinic for Intensive Care Medicine, University Hospital Basel

Basel, 4031, Switzerland

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

D-Limonene

Other

Patient will put the aspUraclip®, a commercially available mini-inhalator filled for our study purpose filled with 1% D-Limonene in the nose for 15 minutes

SLVO

Other

Patient will put the aspUraclip®, a commercially available mini-inhalator filled for our study purpose filled with 1% SLVO in the nose for 15 minutes

Primary outcomes

  1. Change of area under blood glucose curve (AUBGC)

    Time frame: 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

    area under the blood glucose curve (AUBGC) during a mixed-meal test after stimulation with D-Limonene compared to baseline

Secondary outcomes

  1. AUBGC

    Time frame: 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

    AUBGC during a mixed-meal test after stimulation with SLVO compared to baseline

  2. Visual Analogue Scale (VAS score)

    Time frame: 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

    VAS scores on hunger, appetite, nausea, mood, and hedonics of odour and/or taste of the mixed-meal shake, where 0 equals none, and 10 the maximum of each category

  3. Change in plasma insulin levels

    Time frame: 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

    Plasma insulin levels (mIU/L)

  4. Change in plasma peak glucose levels

    Time frame: 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

    Plasma peak glucose levels (mmol/L)

  5. Change in plasma levels of glucagon-like peptide 1 (GLP-1)

    Time frame: 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

    Plasma levels of GLP-1 (pmol/L)

  6. Change in plasma levels of gastric inhibitory polypeptide (GIP)

    Time frame: 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

    Plasma levels of GIP (pmol/L)

  7. Change in plasma levels of Ghrelin

    Time frame: 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

    Plasma levels of Ghrelin (pg/ml)

  8. Change in plasma levels of Leptin

    Time frame: 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

    Plasma levels of Leptin (ng/ml)

  9. Change in plasma levels of Peptide YY (PYY)

    Time frame: 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

    Plasma levels of PYY (pg/ml)

  10. Change in plasma levels of Glucagon

    Time frame: 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

    Plasma levels of Glucagon (pmol/L)

  11. Change in plasma Levels of Interleukin-6

    Time frame: 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

    Plasma Levels of Interleukin-6 (pg/ml)

  12. Change in plasma Levels of C-reactive protein

    Time frame: 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

    Plasma Levels of C-reactive protein (μg/ml)

  13. Change in plasma levels of lipids like LDL-cholesterine, total cholesterine, triglycerides

    Time frame: 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

    Plasma levels of lipids (mmol/L) like LDL-cholesterine, total cholesterine, triglycerides

  14. Change in heart rate

    Time frame: 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

    Heart rate (heart beats per minute)

  15. Change in blood pressure

    Time frame: 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

    blood pressure (mm Hg)

Sponsors and collaborators

Lead sponsor

University Hospital, Basel, Switzerland

Other

Registry information

Official study title

Olfactory Odour Stimulation for Metabolism Control - the "OLFAMET-Study"

Acronym: OLFAMET

Important dates

Study start
2019
Primary completion
2022
Study completion
2022
First posted
Jan 10, 2020
Registry last updated
Dec 6, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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