NCT06217159

Mechanistic Effect of Ketones on Cerebral Blood Flow

The Mechanistic Effect of Ketones on Cerebral Blood Flow and Cerebrovascular Function

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 23 (actual)
• Sponsor: McMaster University · Academic / Other
• Sex: All
• Age: 18 Years – 35 Years
• Healthy volunteers: Accepted

Summary

Oral supplements containing exogenous ketones have recently become available and represent a novel tool for increasing plasma ketone bodies without the need for dietary restriction. Early evidence suggests that oral ketone supplements may enhance cerebral blood flow (CBF). However, a higher dose of a ketone monoester has been shown to slightly lower blood pH and reduce end-tidal CO2 (PetCO2) due to compensatory hyperventilation, which is accompanied by parallel reductions in CBF. Whether reductions in PetCO2 causes reductions in CBF is currently unknown. The purpose of this study is to investigate the effect of manipulating PetCO2 at normocapnia (PetCO2 maintained at baseline) or poikilocapnia (no PetCO2 targeting; breathing room air), following the ingestion of a dose of a ketone monoester on CBF and cerebrovascular reactivity to CO2 in young adults.

Conditions

• Cerebrovascular Function
• Cerebral Blood Flow

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Poikilocapnia	Following ingestion of 0.6 g β-OHB/kg body weight ketone monoester, participants will wear a specialized face mask and breathe room air for 60 min. The face mask will be attached to an automated gas-blender system; however, only room air will be delivered.
DIETARY_SUPPLEMENT	Normocapnia	Following ingestion of 0.6 g β-OHB/kg body weight ketone monoester, participants will be outfitted with a specialized face mask and breathe air with a slightly higher concentration of CO2 to maintain PetCO2 to resting baseline values for 60 min. Gas will be continuously delivered by an automated gas-blender system.

Timeline

• Start date: 2024-01-19
• Primary completion: 2024-05-30
• Completion: 2024-08-31
• First posted: 2024-01-22
• Last updated: 2025-04-23

Locations

1 site across 1 country: Canada