Related Experiment Video
Updated: Jun 6, 2026

Randomized Controlled Trial to Study the Acute Effects of Strength Exercise on Insulin Sensitivity in Obese Adults
Published on: December 1, 2023
Acute, short-term hyperinsulinemia increases olfactory threshold in healthy subjects
1Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, Eberhard Karls University Tübingen, Tübingen, Germany.
Objective:
Smell plays an important role in feeding behavior. We therefore tested whether insulin as a postprandial signal is involved in the regulation of olfactory function.
Research Design And Methods:
We assessed olfactory thresholds in eight lean subjects (age: 34 ± 7 years, M/F: 5/3) before and during a 2-h hyperinsulinemic (1 mU kg(-1) min(-1)) euglycemic clamp and in eight lean fasted subjects (age: 36 ± 6 years, M/F: 5/3) without insulin infusion at the same time of the day. To define odor thresholds, standardized 'sniffing sticks' were used.
Results:
Odor thresholds decreased from 7.8 ± 1.2 to 6.2 ± 1.1 during euglycemic hyperinsulinemia (P=0.0173), representing an increase in odor threshold. In the control group, odor thresholds were 8.3 ± 1.6 and did not change after 120 min of fasting (8.9 ± 2.2, P=0.6).
Conclusions:
Increased insulin levels lead to a reduced smelling capacity, potentially reducing the pleasantness of eating. Therefore, insulin action in the olfactory bulb may be involved in the process of satiation and may thus be of interest in the pathogenesis of obesity.
Related Concept Videos
Hyperglycemia
Hypoglycemia and Glucagon
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are co-secreted in...
Insulin: Dosing Regimen and Adverse Effects
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...
Type I Diabetes III: Clinical Manifestations
Olfactory Receptors: Location and Structure
