School of Health and Human Performance, Dublin City University, Dublin, Ireland.
Healthspan, Resilience and Performance Research, Florida Institute for Human and Machine Cognition, Pensacola, Florida, USA.
Exp Physiol. 2024 Oct;109(10):1672-1682. doi: 10.1113/EP091794. Epub 2024 Aug 27.
Exogenous ketone supplements are a potential augmentation strategy for cognitive resilience during acute hypoxic exposure due to their capacity to attenuate the decline in oxygen (O) availability, and by providing an alternative substrate for cerebral metabolism. Utilizing a single-blind randomized crossover design, 16 male military personnel (age, 25.3 ± 2.4 year, body mass, 86.2 ± 9.3 kg) performed tests of cognitive performance at rest in three environments: room air (baseline), normoxia (20 min; 0 m; 20.9% O) and hypoxia (20 min; 6096 m, 9.7% O) using a reduced O breathing device (ROBD). (R)-3-Hydroxybutyl (R)-3-hydroxybutyrate (R-BD R-βHB) ketone monoester (KME; 650 mg/kg, split dose given at 30 min prior to each exposure) or taste-matched placebo (PLA) was ingested prior to normoxia and hypoxic exposure. Blood R-βHB and glucose concentrations, cognitive performance and O saturation ( ) were collected throughout. KME ingestion increased blood R-βHB concentration, which was rapid and sustained (>4 mM 30 min post; P < 0.001) and accompanied by lower blood glucose concentration (∼20 mg/dL; P < 0.01) compared to PLA. Declines in cognitive performance during hypoxic exposure, assessed as cognitive efficiency during a Defense Automated Neurobehavioral Assessment (DANA) code substitution task, were attenuated with KME leading to 6.8 (95% CL: 1.0, 12.6) more correct responses per minute compared to PLA (P = 0.018). The decline in during hypoxic exposure was attenuated (6.40% ; 95% CL: 0.04, 12.75; P = 0.049) in KME compared to PLA (KME, 76.8 ± 6.4% ; PLA, 70.4 ± 7.4% ). Acute ingestion of KME attenuated the decline in cognitive performance during acute severe hypoxic exposure, which coincided with attenuation of declines in O saturation.
外源性酮补充剂是一种潜在的认知弹性增强策略，因为它们能够减轻氧气（O）供应的下降，并为大脑代谢提供替代底物。利用单盲随机交叉设计，16 名男性军事人员（年龄 25.3±2.4 岁，体重 86.2±9.3 公斤）在三种环境下进行认知表现测试：在房间空气（基线）、常氧（20 分钟；0 米；20.9%O）和缺氧（20 分钟；6096 米，9.7%O）下，使用减少 O 呼吸设备（ROBD）。（R）-3-羟基丁酸（R）-3-羟基丁酸酯（R-BD R-βHB）单酯（KME；650mg/kg，在每次暴露前 30 分钟分成两次给予）或口味匹配的安慰剂（PLA）在常氧和缺氧暴露前给予。整个过程中收集血液 R-βHB 和葡萄糖浓度、认知表现和 O 饱和度（ ）。KME 摄入增加了血液 R-βHB 浓度，该浓度迅速且持续（>4mM 30 分钟后；P<0.001），同时伴有较低的血糖浓度（约 20mg/dL；P<0.01），与 PLA 相比。与 PLA 相比，KME 减轻了缺氧暴露期间认知表现的下降，评估为防御自动化神经行为评估（DANA）代码替代任务期间的认知效率，每分钟导致正确反应多 6.8（95%CL：1.0，12.6）（P=0.018）。与 PLA 相比，KME 减轻了缺氧暴露期间的下降（6.40%；95%CL：0.04，12.75；P=0.049）（KME，76.8±6.4%；PLA，70.4±7.4%）。急性摄入 KME 减轻了急性严重缺氧暴露期间认知表现的下降，这与 O 饱和度下降的减轻相一致。
