更多的体育锻炼和更好的睡眠与老年人认知能力下降和痴呆的风险降低有关。但人们对它们与脑功能和神经病理学的综合联系知之甚少。这项研究调查了活动记法估计的身体活动总量(TVPA)与睡眠模式之间潜在的独立和交互式横截面关系[即,总睡眠时间(TST),睡眠效率(SE)]使用静息状态功能磁共振成像(rs-fMRI)测量的大规模网络连接和淀粉样蛋白β的正电子发射断层扫描(PET)测量。参与者是来自BIOCARD研究的135名非痴呆的老年人(116名认知正常,19名轻度认知障碍;平均年龄=70.0岁)。使用多元线性回归分析,我们评估了TVPA,TST,和SE在默认模式下连接,显著性,和顶叶控制网络,随着网络模块化,网络隔离的度量。较高的TVPA和SE与较高的网络模块性独立相关,尽管SE与模块化的正相关仅存在于淀粉样蛋白阴性个体中。此外,较高的TVPA与默认模式网络中更大的连接性相关联,而更高的SE与显著性网络内更大的连通性有关。相比之下,较长的TST与较低的网络模块性有关,特别是在淀粉样蛋白阳性个体中,表明更长的睡眠时间和更大的网络混乱之间的关系。身体活动和睡眠测量与淀粉样蛋白阳性无关。这些数据表明,更高的身体活动水平和更有效的睡眠可能会促进更隔离和潜在的弹性功能网络,并增加特定大规模网络内的功能连通性,睡眠和功能网络连接之间的关系可能取决于淀粉样蛋白状态。
Greater physical activity and better sleep are associated with reduced risk of cognitive decline and dementia among older adults, but little is known about their combined associations with measures of brain function and neuropathology. This study investigated potential independent and interactive cross-sectional relationships between actigraphy-estimated total volume of physical activity (TVPA) and sleep patterns [i.e., total sleep time (TST), sleep efficiency (SE)] with resting-state functional magnetic resonance imaging (rs-fMRI) measures of large scale network connectivity and positron emission tomography (PET) measures of amyloid-β. Participants were 135 non-demented older adults from the BIOCARD study (116 cognitively normal and 19 with mild cognitive impairment; mean age = 70.0 years). Using multiple linear regression analyses, we assessed the association between TVPA, TST, and SE with connectivity within the default-mode, salience, and fronto-parietal control networks, and with network
modularity, a measure of network segregation. Higher TVPA and SE were independently associated with greater network
modularity, although the positive relationship of SE with
modularity was only present in amyloid-negative individuals. Additionally, higher TVPA was associated with greater connectivity within the default-mode network, while greater SE was related to greater connectivity within the salience network. In contrast, longer TST was associated with lower network
modularity, particularly among amyloid-positive individuals, suggesting a relationship between longer sleep duration and greater network disorganization. Physical activity and sleep measures were not associated with amyloid positivity. These data suggest that greater physical activity levels and more efficient sleep may promote more segregated and potentially resilient functional networks and increase functional connectivity within specific large-scale networks and that the relationship between sleep and functional networks connectivity may depend on amyloid status.