Clinical trial NCT03929419: "Effect of Central Insulin Administration on Whole-body Insulin Sensitivity in Women"
Official title: "Effect of Central Insulin Administration on Whole-body Insulin Sensitivity in Women"
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Insulin Sensitivity
Lead sponsor: University Hospital Tuebingen
Sponsor class: OTHER
First posted: 2019-04-26
Enrollment: 29
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: The human brain is an insulin sensitive organ. Brain insulin action modulates peripheral insulin sensitivity in young lean men. As a underlying mechanism, the investigators previously detected suppression of endogenous glucose production and stimulation of glucose disappearance to peripheral tissue in response to brain insulin delivery by nasal spray. Whether this holds true in young woman is unknown, since differences in brain insulin response between sexes have been reported. The investigators will address this question by combining the delivery of insulin to the brain as nasal spray with hyperinsulinemic euglycemic clamp experiments in natural cycling women.

In the planned randomized, placebo controlled cross-over study, female participants will undergo four hyperinsulinemic euglycemic experiments with tracer dilution, two in the first phase and two in the second phase of their menstrual cycle. On one of the study days per menstrual phase, subjects will receive intranasal insulin administration, on the other placebo spray. The protocol has been successfully applied previously in men. Based on the results of this trial, the investigators calculated a required sample size of N=10 for the planned study in women.

These experiments will help to better understand the role of brain insulin action in a broader sense. The results can be the basis for larger clinical trials that address the sex-specific impact of brain insulin resistance for glucose metabolism and diabetes risk.

Detailed description: "Effect of central insulin administration on whole-body insulin sensitivity in women" The human brain is an insulin sensitive organ. Brain insulin action modulates peripheral insulin sensitivity in young lean men. As a underlying mechanism, the investigators previously detected suppression of endogenous glucose production and stimulation of glucose disappearance to peripheral tissue in response to brain insulin delivery by nasal spray. Whether this holds true in young woman is unknown, since differences in brain insulin response between sexes have been reported. The investigators will address this question by combining the delivery of insulin to the brain as nasal spray with hyperinsulinemic euglycemic clamp experiments in natural cycling women.

In the planned randomized, placebo controlled cross-over study, female participants will undergo four hyperinsulinemic euglycemic experiments with tracer dilution, two in the first phase and two in the second phase of their menstrual cycle. On one of the study days per menstrual phase, subjects will receive intranasal insulin administration, on the other placebo spray. The protocol has been successfully applied previously in men. Based on the results of this trial, the investigators calculated a required sample size of N=10 for the planned study in women.

These experiments will help to better understand the role of brain insulin action in a broader sense. The results can be the basis for larger clinical trials that address the sex-specific impact of brain insulin resistance for glucose metabolism and diabetes risk.

Eligibility criteria: Inclusion Criteria:

* female volunteer adults
* HbA1c \<6.0%
* Age between 18 and 30 years
* Standard routine laboratory
* No underlying diseases
* No medication
* No hormonal contraception
* Understanding of the explanations of the study and the instructions

Exclusion Criteria:

* Persons with limited temperature perception and / or increased temperature Sensitivity to warming of the body
* Cardiovascular disease, such as manifest coronary Heart disease, heart failure greater than NYHA 2, recent myocardial infarction
* People with a hearing disorder or increased sensitivity to loud Sounds
* persons with claustrophobia
* Minors or non-consenting subjects are also excluded
* Pregnancy or breastfeeding women
* Surgery less than 3 months ago
* Simultaneous participation in other interventional studies
* Acute illness or infection within the last 4 weeks
* Neurological and psychiatric disorders
* Subjects with hemoglobin Hb \<12g / dl (at screening)
* Allergic diseases
* Individuals with a history of heparin-induced thrombocytopenia (HIT)

Primary outcomes:
measure: Change in the peripheral insulin sensitivity
timeFrame: 60-90 minutes and 150-210 minutes during euglycemic clamp
Secondary outcomes:
measure: Correlation with autonomous nervous system activity
timeFrame: 70-80 minutes and 190-200 minutes during euglycemic clamp
measure: Differential effects dependent on female sexual hormones
timeFrame: 60-90 minutes and 150-210 minutes during euglycemic clamp
measure: Effect of menstrual cycle on insulin sensitivity before spray application
timeFrame: 60-90minutes
measure: Effect of menstrual cycle on brain insulin sensitivity
timeFrame: 60-90 minutes
measure: Effect of menstrual cycle on processing of food cues in the brain
timeFrame: 20 minutes
Other outcomes:
Locations:
city: Tuebingen
country: Germany
facility: University of Tuebingen, Department of Internal Medicine IV
Study officials:
References: