Effect of Weight Loss on Brain Insulin Sensitivity in Humans

Effekt Von Gewichtsabnahme Auf Die zentralnervöse Insulinresistenz Des Menschen

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.

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