Impact of Intranasal Insulin on Sympathetic Activity and Cerebral Vasodilation

Early Phase 1

Active, not recruiting

• Conditions: Healthy; Vasodilation; Insulin Resistance; Autonomic Dysfunction; Obesity
• Interventions: Other: Carbon dioxide breathing; Other: Neurovascular Coupling; Drug: Human insulin

• Registration Number: NCT05153395
• Lead Sponsor: University of Missouri-Columbia

Brief Summary

The purpose of this project is to examine the impact of increases in brain insulin on sympathetic nervous system activity, as well as peripheral and cerebral blood flow in humans.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-11-18
• Study Start: 2021-12-01
• Study First Submitted QC: 2021-12-08
• Study First Posted: 2021-12-10
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-24
• Last Update Posted: 2025-03-28
• Primary Completion: 2026-06
• Study Completion: 2026-06

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 65

Inclusion Criteria

• healthy adult men and women;
• 18-45 years of age;
• BMI >18 kg/m2;
• non-pregnant/non-breastfeeding;
• non-nicotine users;

Exclusion Criteria

• taking any medications known to affect metabolic, respiratory, cardiovascular, and/or autonomic

Self-reported history of:

• hepatic, renal, pulmonary, cardiovascular, or neurological disease;
• stroke or neurovascular disease;
• bleeding/clotting disorders;
• sleep apnea or other sleep disorders;
• diabetes;
• smoking;
• history of alcoholism or substance abuse;
• hypertension;
• respiratory disease;
• active cancer;
• autoimmune disease.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Insulin (Doppler)	Carbon dioxide breathing	Human insulin (160 IU) will be administered as a bolus using an intra-nasal device.
Insulin (Doppler)	Neurovascular Coupling	Human insulin (160 IU) will be administered as a bolus using an intra-nasal device.
Insulin (MRI)	Carbon dioxide breathing	Human insulin (160 IU) will be administered as a bolus using an intra-nasal device.
Time Control (Doppler)	Carbon dioxide breathing	Time control only
Time Control (Doppler)	Neurovascular Coupling	Time control only
Insulin (Doppler)	Human insulin	Human insulin (160 IU) will be administered as a bolus using an intra-nasal device.
Insulin (MRI)	Human insulin	Human insulin (160 IU) will be administered as a bolus using an intra-nasal device.

Primary Outcome Measures

Name	Time	Method
Amount of cerebral blood flow	Change from baseline at minute 15	Measured with trans-cranial Doppler ultrasound (cm/s) or arterial spin labeling (mL/100 g/min)

Secondary Outcome Measures

Name	Time	Method
Amount of muscle sympathetic nerve activity (MSNA)	Change from baseline at minute 15	MSNA burst incidence (bursts/100 heart beats)
Amount of leg blood flow	Change from baseline at minute 15	Measured with Doppler ultrasound (mL/min)

Trial Locations

Locations (1)

University of Missouri; 🇺🇸 Columbia, Missouri, United States