Supplementary information files for Sedentary behaviour, but not moderate-to-vigorous physical activity, is associated with respiratory responses to acute psychological stress

Supplementary files for article Sedentary behaviour, but not moderate-to-vigorous physical activity, is associated with respiratory responses to acute psychological stress Background Acute psychological stress induces respiratory responses, and stress-induced respiratory changes can be used to non-invasively reflect metabolic regulation. Respiratory and cardiovascular responses to stress are both driven by sympathetic mechanisms. Higher volumes of sedentary behaviour and lower volumes of physical activity are associated with elevated sympathetic tone and larger cardiovascular responses to stress. The aim of this study was to test whether these associations translate to measures of respiratory stress reactivity. Methods Daily hours of sedentary behaviour (thigh-mounted activPAL) and moderate-to-vigorous physical activity (MVPA; wrist-mounted ActiGraph) were assessed across seven days. Breath-by-breath respiratory (e.g., breathing frequency [BF], end-tidal carbon dioxide partial pressure [PetCO2], carbon dioxide output [V̇CO2] and respiratory exchange ratio [RER]) responses to an 8-min Paced Auditory Serial Addition Test were then measured using a Cortex MetaLyzer3B. Results Healthy participants (N = 61, mean age ± SD = 25.7 ± 8.9 years) recorded high volumes of sedentary behaviour (9.96 ± 1.48 hours/day) and MVPA (1.70 ± 0.71 hours/day). In adjusted models (with the inclusion of sedentary behaviour, MVPA, and other a priori selected covariates) hours of daily sedentary behaviour were associated with baseline to stress changes in BF (Β = 0.695, 95% CI = 0.281 — 1.109, p =.014), VT (Β = -0.042, 95% CI = -0.058 — -0.026, p =.014), PetCO2 (Β = -0.537, 95% CI = -0.829 — -0.245, p =.014), V̇CO2 (Β = -0.008, 95% CI = -0.014 — -0.003, p =.030), and RER (Β = -0.013, 95% CI = -0.021 — -0.005, p =.022). Daily hours of MVPA were not linked with respiratory responses to stress. Discussion Sedentary behaviour, but not MVPA, is associated with respiratory stress reactivity. Future work should untangle the underlying mechanisms of these findings and explore the consequences for cardiometabolic disease.

论文《久坐行为（Sedentary behaviour）而非中等至高强度体力活动（moderate-to-vigorous physical activity, MVPA）与急性心理应激（acute psychological stress）的呼吸反应相关》补充材料

背景 急性心理应激可诱发呼吸反应，且应激诱导的呼吸变化可无创反映代谢调控。机体对应激的呼吸与心血管反应均由交感神经机制介导。久坐行为时长更长、体力活动时长更短与交感神经张力升高及应激时更大的心血管反应相关。本研究旨在验证上述关联是否同样适用于呼吸应激反应性的评估。

方法 研究对受试者为期7天的每日久坐行为时长（通过佩戴于大腿的activPAL设备）与中等至高强度体力活动（MVPA；通过佩戴于手腕的ActiGraph设备）进行评估。随后，采用Cortex MetaLyzer3B对8分钟Paced听觉连续加法测验（Paced Auditory Serial Addition Test）过程中的逐次呼吸呼吸反应（如呼吸频率（breathing frequency, BF）、潮气末二氧化碳分压（end-tidal carbon dioxide partial pressure, PetCO2）、二氧化碳排出量（carbon dioxide output, V̇CO2）、潮气量（VT）及呼吸交换率（respiratory exchange ratio, RER））进行测量。

结果 本研究纳入61名健康受试者，平均年龄±标准差为25.7±8.9岁，其日均久坐行为时长为9.96±1.48小时，日均MVPA时长为1.70±0.71小时。在纳入久坐行为、MVPA及其他先验选定协变量的校正模型中，每日久坐行为时长与BF、VT、PetCO2、V̇CO2及RER从基线到应激状态的变化显著相关（BF：Β=0.695，95%置信区间CI=0.281—1.109，p=0.014；VT：Β=-0.042，95%CI=-0.058—-0.026，p=0.014；PetCO2：Β=-0.537，95%CI=-0.829—-0.245，p=0.014；V̇CO2：Β=-0.008，95%CI=-0.014—-0.003，p=0.030；RER：Β=-0.013，95%CI=-0.021—-0.005，p=0.022）；每日MVPA时长与应激相关呼吸反应无显著关联。

讨论 久坐行为而非MVPA与呼吸应激反应性相关。未来研究应阐明该发现的潜在机制，并探讨其对心血管代谢疾病的影响。