Influence Of Exogenous Ketosis On Exercise Pressor Responses And Cardiovagal Baroreflex Sensitivity In Metabolic Syndrome

PURPOSE: Recently, exogenous ketone ester (KE) administration has been shown to significantly improve indices of vascular and metabolic function individuals with obesity, and thus, may also have implications for correcting cardiovascular abnormalities in individuals with MetS. Thus, this study tested the hypothesis that exogenous KE administration would elicit transient reductions in exercise pressor responses while simultaneously increasing cBRS in individuals with MetS. METHODS: 11 individuals participated in this study, 7 of whom met the criteria for MetS. Each participant completed three study visits, which included a cardiometabolic prescreening (visit 1) and two experimental visits (visits 2 and 3). During each experimental visit, participants ingested either an oral dose of a commercially available exogenous KE (~280 mg/kg) or a taste- and volume-matched placebo (random order). Exercise pressor responses were quantified as the changes in mean arterial pressure (ΔMAP; collected beat-by-beat via finger photoplethysmography) during two-minutes of isometric handgrip exercise (35% of the maximal voluntary contraction) and were assessed before (BL), and 30-, and 60-minutes post ingestion. Likewise, cBRS was evaluated using the sequence method (systolic blood pressure change >1.0 mmHg, pulse interval change >5.0 ms, r > 0.80, sequence length > 3 beats), and was assessed before (BL), and 45-, and 105-minutes post ingestion. RESULTS: A significant condition by time interaction was observed for ΔMAP (F = 7.036, p = 0.01) in the MetS group. Further inspection suggests this may be explained by a net decrease in the ΔMAP response at minute 30 in the KE condition (mean diff: -9.49 ΔmmHg), but a net increase at minute 30 in the placebo condition (mean diff: +3.65 ΔmmHg). significant condition by time interactions were also observed for cBRS in the KE, but not placebo conditions in both the MetS (F = 4.11, p = 0.04) and control groups (F = 4.719, p = 0.03). Further inspection indicates these interactions may be mediated by decreases in cBRS during the KE condition that were not observed in the placebo condition. CONCLUSIONS: Based on these preliminary data, exogenous KE may transiently attenuate exercise pressure responses in individuals with MetS, while also acutely reducing cBRS. University of Southern Mississippi, NIH U54GM115428