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Effect of Weight Loss on Brain Insulin Sensitivity in Humans

Not Applicable
Recruiting
Conditions
Insulin Resistance
Interventions
Other: nasal insulin
Other: placebo spray
Registration Number
NCT02991365
Lead Sponsor
University Hospital Tuebingen
Brief Summary

Obesity if known to be associated with brain insulin resistance in humans. This condition has not only implication for the brain but also for whole-body energy homeostasis. Research in rodents indicates that weight loss is able to improve insulin sensitivity of the brain. The current project will test this hypothesis in humans. Therefore, brain insulin sensitivity will be assessed by fMRI in combination with intranasal insulin administration, using an established protocol. Furthermore, effects of daily administration of insulin nasal spray (versus placebo) over 8 weeks will be assessed as secondary (exploratory) variables.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
40
Inclusion Criteria
  • HbA1c <6.5%
  • Age between 40 and 75 years
  • No intake of antidiabetic drugs or drugs for weight reduction
  • no steroid intake
  • Stable medication over 10 weeks before the start of the study
Exclusion Criteria
  • Persons who wear non-removable metal parts in or on the body.
  • Persons with reduced temperature sensitivity and / or increased sensitivity to heating of the body
  • Cardiovascular disease can not be ruled out, e.g. manifest coronary heart disease, heart failure greater than NYHA 2, previous heart attack, stroke condition
  • Persons with hearing impairment or increased sensitivity to loud noises
  • People with claustrophobia
  • Minors or non-consenting subjects are also excluded
  • Subjects with an operation less than 3 months
  • Simultaneous participation in other studies
  • Neurological and psychiatric disorders
  • Subjects with hemoglobin Hb <11 g / dl
  • Hypersensitivity to any of the substances used

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
nasal insulinnasal insulindaily administration of 160 U of human insulin as nasal spray
placebo sprayplacebo spraydaily administration of placebo solution as nasal spray
Primary Outcome Measures
NameTimeMethod
brain insulin sensitivity30 minutes after administration of nasal insulin

fMRI measurement will be performed before and after administration of 160 U of human insulin as nasal spray. Changes in regional activity will be quantified to assess regional brain insulin sensitivity.

Secondary Outcome Measures
NameTimeMethod
Cognitive function1 hours

cognitive function will be addressed by neuropsychological testing.

Glucose tolerance2 hours

a 75 g oral glucose tolerance test will be performed. Glucose tolerance will be defined by the American Diabetes Association criteria.

Effect of daily administration of 160 U nasal insulin or placebo over 8 weeks on body weight.8 weeks

Participants will receive nasal insulin or placebo in a double-blind randomized fashion. Before and after 8 weeks body weight will be recorded.

whole-body insulin sensitivity2 hours

Insulin sensitivity will be estimated from a frequent-sampling 75 g oral glucose tolerance test using the Matsuda formula.

Effect of daily administration of 160 U nasal insulin or placebo over 8 weeks on body composition .8 weeks

Participants will receive nasal insulin or placebo in a double-blind randomized fashion. Before and after 8 weeks body composition will be addressed by whole-body MRI and liver MRS.

Effect of daily administration of 160 U nasal insulin or placebo over 8 weeks on glucose tolerance .8 weeks

Participants will receive nasal insulin or placebo in a double-blind randomized fashion. Before and after 8 weeks glucose tolerance will be assessed using a 75 g oral glucose tolerance test.

Trial Locations

Locations (1)

University of Tuebingen, Department of Internal Medicine IV

🇩🇪

Tübingen, Germany

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