Effects of Intranasal Insulin Administration on Tissue Specific Insulin Sensitivity

• Status: Completed
• Trial end date: 2016-12-01
• Target enrollment: 0
• Participant gender: Male

Summary

Recent research has suggested that intranasally administered insulin can reach the brain quickly without passing through circulation and evoke increased insulin sensitivity and tissue glucose consumption during insulin stimulation (low-dose hyperinsulinemic, euglycemic clamp). It is still not known what mechanism causes these changes or what tissues are involved in this.

In this study, the changes in tissue-specific insulin sensitivity and glucose uptake will be investigated by using glucose-analogue radiotracer ([18F]-fluorodeoxyglucose) with positron emission tomography (PET) imaging during insulin stimulation. Ten healthy males are studied, each receiving nasal sprays containing insulin or placebo in a randomized order on two separate days. After spray administration, glucose uptake in skeletal muscle, liver, subcutaneous and visceral adipose tissue, myocardium, intestines, brown adipose tissue and brain assessed by PET imaging and glucose uptake in these tissues is analyzed. Endogenous glucose production is calculated facilitating the measurements glucose and radiotracer uptake in tissues and tracer loss into urine.

As skeletal muscle consumes most of the glucose available, it is likely that administration of insulin sprays will result in an increased uptake in this tissue. Some increase in glucose uptake might also be seen in other tissue types after insulin spray versus placebo spray administration.

• Phase: N/A
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Turku University Hospital
• Collaborator: University Hospital Tuebingen
• Treatments: Insulin; Insulin Aspart; Insulin Detemir; Insulin, Globin Zinc

Criteria

Inclusion Criteria:

1. BMI 18,5-25 kg/m2

2. Fasting plasma glucose less than 6.1 mmol/l

3. Normal 2-hour oral glucose tolerance test (OGTT)

Exclusion Criteria:

1. Any chronic disease or medication that could affect glucose metabolism

2. History of anorexia nervosa or bulimia

3. Smoking of tobacco, taking of snuffs, or use of narcotics

4. Abusive use of alcohol

5. Any other condition that in the opinion of the investigator could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results