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Acute Cardiovascular Response to Exogenous Ketosis During Rest and Maximal Exercise

Crabtree, Christopher David
http://orcid.org/0000-0001-7284-3048
http://rave.ohiolink.edu/etdc/view?acc_num=osu1712657722209343

Abstract Details

2024, Doctor of Philosophy, Ohio State University, Kinesiology.
Introduction: Various methods of achieving beneficial levels of ketones have been theorized to serve as a potential therapeutic for patients suffering from heart failure. Ketone uptake by the heart is rapid and may serve as an efficient alternative fuel that bypasses myocardial metabolic dysfunction. Ketones may also work through other pleiotropic mechanisms (e.g., hemodynamic, cell signaling) to impact cardiac performance. To further elucidate the influence of ketones on cardiovascular responses, two exploratory studies were performed here in separate cohorts of healthy adults to investigate the effects of 50g ketone ester (KE) ingestion on resting and exercise-induced metabolic and cardiovascular responses. Methods: 1) Study 1: This was a single visit acute imaging and supplementation study (n = 20). Subjects reported to the MRI facility following an overnight fast and underwent baseline cardiovascular imaging including quantitative myocardial perfusion. Subjects then consumed the test article, ketone ester (KE) or placebo (PL) and underwent repeated cardiac imaging every 15-30min. Two hours following consumption, subjects underwent a final imaging scan and received a final quantitative perfusion acquisition. Ketones and glucose were measured at baseline and every imaging timepoint. 2) Study 2: A cohort of recreationally active adults (n = 12) were enrolled to complete a double blind, balanced, crossover study to examine the effects of KE ingestion compared to a calorically-matched fat-based placebo on measures of maximal oxygen consumption (VO2max) and running efficiency. Subjects presented to the testing facility fasted then underwent baseline fingersticks and drank the supplement immediately after. Metabolic and cardiovascular measures were collected every 15-30min following supplementation. Two hours following ingestion, the subject began the Bruce Protocol maximal exercise test. Results: 1) Study 1: Following KE consumption venous beta-hydroxybutyrate (BHB) increased reaching 2.1 mM two hours post-consumption. Left ventricular (LV) cardiac output (CO) was elevated compared to PL at every timepoint following consumption (p < .05) and increased by 33% from baseline two hours following KE ingestion. CO elevation was attributed to increased stroke volume (SV) and heart rate (HR), which increased by 11% (p = .02) and 22% (p < .001) from baseline, respectively. After KE MBF increased approximately 29% from baseline (p < .001). PL did not induce any differences from baseline two hours post-consumption. 2) Study 2: BHB rapidly elevated following KE consumption reaching 2.4mM two hours post-consumption. During the initial resting phase, elevations in heart rate (HR) (p = .001) and resting VO2 (p = .002) were observed after KE supplementation. There were no differences in exercise duration between supplement conditions. Despite this, VO2max was reduced after KE. There were no differences in exercise-induced lactate, RER, or RPE responses between groups. Conclusions: Ketone ester consumption rapidly elevates venous BHB and measures of resting cardiovascular function including heart rate, stroke volume and CO in healthy adults. During maximal exercise, KE ingestion reduced oxygen consumption for the same workload, implying improved exercise efficiency. Collectively, this work indicates that increasing the availability of ketones via 50g of exogenous ketones differentially augments cardiovascular performance dependent on physiological state and exercise workload.
Jeff Volek (Advisor)
Orlando Simonetti (Committee Member)
Yuchi Han (Committee Member)
Brian Focht (Committee Member)
153 p.
Kinesiology; Physiology
Ketones; Cardiac Function; MRI; CMR; Exercise Performance; Ketone Ester

Recommended Citations

Citations

  • Crabtree, C. D. (2024). Acute Cardiovascular Response to Exogenous Ketosis During Rest and Maximal Exercise [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1712657722209343

    APA Style (7th edition)

  • Crabtree, Christopher. Acute Cardiovascular Response to Exogenous Ketosis During Rest and Maximal Exercise. 2024. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1712657722209343.

    MLA Style (8th edition)

  • Crabtree, Christopher. "Acute Cardiovascular Response to Exogenous Ketosis During Rest and Maximal Exercise." Doctoral dissertation, Ohio State University, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=osu1712657722209343

    Chicago Manual of Style (17th edition)

osu1712657722209343
© 2024, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.