University of South Carolina, Columbia, SC, 29208, USA.
Wake Forest School of Medicine, Winston-Salem, NC, USA.
BMC Cancer. 2018 Jun 25;18(1):685. doi: 10.1186/s12885-018-4603-3.
Evidence suggests reallocating daily sedentary time to physical activity or sleep confers important health benefits in cancer survivors. Despite emerging research suggesting physical activity as a treatment for cancer-related cognitive impairment (CRCI), little is known about the interactive effects of behaviors across the 24-h period. The present purpose was to examine the cognitive effects of reallocating sedentary time to light-intensity physical activity, moderate-to-vigorous physical activity (MVPA), or sleep in breast cancer survivors.
Breast cancer survivors (N = 271, Mage = 57.81 ± 9.50 years) completed iPad-based questionnaires and cognitive tasks assessing demographics, health history, executive function, and processing speed (Task-Switch, Trail Making). Participants wore an accelerometer for seven consecutive days to measure their sedentary, physical activity, and sleep behaviors. Single effects (each behavior individually) and partition (controlling for other behaviors) models were used to examine associations among behaviors and cognitive performance. Isotemporal substitution models were used to test the cognitive effects of substituting 30 min of sedentary time with 30 min of light-intensity activity, MVPA, and sleep.
MVPA was associated with faster Task-switch reaction time in the partition models (stay: B = - 35.31, p = 0.02; switch: B = - 48.24, p = 0.004). Replacing 30 min of sedentary time with 30 min of MVPA yielded faster reaction times on Task-Switch stay (B = - 29.37, p = 0.04) and switch (B = - 39.49, p = 0.02) trials. In Trails A single effects models, sedentary behavior was associated with faster completion (B = - 0.97, p = 0.03) and light-intensity activity with slower completion (B = 1.25, p = 0.006). No single effects were observed relative to Trails B completion (all p > 0.05). Only the effect of MVPA was significant in the partition models (Trails A: B = - 3.55, p = 0.03; Trails B: B = - 4.46, p = 0.049). Replacing sedentary time with light-intensity activity was associated with slower Trails A (B = 1.55 p = 0.002) and Trails B (B = 1.69, p = 0.02) completion. Replacing light activity with MVPA yielded faster Trails A (B = - 4.35, p = 0.02) and Trails B (B = - 5.23, p = 0.03) completion.
Findings support previous research suggesting MVPA may be needed to improve cognitive function in breast cancer survivors. Trails findings underscore the need to dissect sedentary contexts to better understand the impact of daily behavioral patterns on CRCI. Additional research investigating the cognitive impacts of behaviors across the 24-h period is warranted.
This study is registered with United States ClinicalTrials.gov ( NCT02523677 ; 8/14/2015).
有证据表明，将日常久坐时间重新分配到体力活动或睡眠中，可使癌症幸存者获得重要的健康益处。尽管有新的研究表明体力活动是治疗与癌症相关的认知障碍（CRCI）的一种方法，但对于 24 小时内行为的相互作用知之甚少。本研究旨在探讨将久坐时间重新分配到低强度体力活动、中等到剧烈体力活动（MVPA）或睡眠对乳腺癌幸存者认知的影响。
共有 271 名乳腺癌幸存者（平均年龄 57.81±9.50 岁）完成了基于 iPad 的问卷调查和认知任务，评估了人口统计学、健康史、执行功能和处理速度（任务切换、轨迹生成）。参与者佩戴加速度计连续 7 天，以测量他们的久坐、体力活动和睡眠行为。使用单一效应（每种行为单独）和分区（控制其他行为）模型来检查行为之间的关联和认知表现。等时替代模型用于测试用 30 分钟的低强度活动、MVPA 和睡眠替代 30 分钟久坐时间的认知效果。
在分区模型中，MVPA 与任务切换反应时间的加快有关（保持：B=-35.31，p=0.02；转换：B=-48.24，p=0.004）。用 30 分钟 MVPA 替代 30 分钟的久坐时间可使任务切换保持（B=-29.37，p=0.04）和转换（B=-39.49，p=0.02）试验的反应时间更快。在 Trails A 的单一效应模型中，久坐行为与完成速度更快有关（B=-0.97，p=0.03），而低强度活动与完成速度较慢有关（B=1.25，p=0.006）。Trails B 完成（所有 p>0.05）没有观察到单一效应。只有 MVPA 的效应在分区模型中是显著的（Trails A：B=-3.55，p=0.03；Trails B：B=-4.46，p=0.049）。用低强度活动替代久坐时间与 Trails A（B=1.55，p=0.002）和 Trails B（B=1.69，p=0.02）完成的速度较慢有关。用 MVPA 替代低强度活动可使 Trails A（B=-4.35，p=0.02）和 Trails B（B=-5.23，p=0.03）完成的速度更快。
研究结果支持先前的研究，表明 MVPA 可能是改善乳腺癌幸存者认知功能所必需的。Trails 的研究结果强调需要剖析久坐的背景，以更好地了解日常行为模式对 CRCI 的影响。有必要进行更多的研究，以调查 24 小时内行为的认知影响。
本研究在美国临床试验数据库注册（NCT02523677；2015 年 8 月 14 日）。
