Salomon Amit, Galperin Irina, Buzaglo David, Mirelman Anat, Regev Keren, Karni Arnon, Schmitz-Hübsch Tanja, Paul Friedemann, Devos Hannes, Sosnoff Jacob J, Gazit Eran, Tamir Raz, Shimoni Nathaniel, Hausdorff Jeffrey M
Center for the Study of Movement, Cognition and Mobility, Neurological Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Center for the Study of Movement, Cognition and Mobility, Neurological Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Neurology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Mult Scler Relat Disord. 2022 Dec;68:104108. doi: 10.1016/j.msard.2022.104108. Epub 2022 Aug 18.
Physical activity is lower in people with multiple sclerosis (pwMS) compared to healthy controls. Previous work focused on studying activity levels or activity volume, but studies of daily-living rest-activity fragmentation patterns, circadian rhythms, and fractal regulation in pwMS are limited. Based on findings in other cohorts, one could suggest that these aspects of daily-living physical activity will provide additional information about the health and well-being of pwMS. Therefore, here, we aimed to (1) identify which fragmentation, fractal, and circadian amplitude measures differ between pwMS and healthy controls, (2) evaluate the relationship between fragmentation, fractal, and circadian amplitude measures and disease severity, and (3) begin to evaluate the added value of those measures, as compared to more conventional measures of physical activity (e.g., mean signal vector magnitude (SVM). A global measure of the overall volume of physical activity).
132 people with relapsing-remitting MS (47±11 yrs, 69.7% female, Expanded Disability Status Scale, EDSS, median (IQR): 3 (2-4)) and 90 healthy controls (46±11 yrs, 47.8% female) were asked to wear a 3D accelerometer on their lower back for 7 days. Rest-activity fragmentation, circadian amplitude, fractal regulation, and mean SVM metrics were extracted. PwMS and healthy controls were compared using independent samples t-tests and linear regression, including comparisons adjusted for mean SVM to control for the effect of physical activity volume. Spearman correlations between measures and logistic regressions were used to identify the clinical condition based on the measures that differed significantly after adjusting for SVM. All analyses included adjustments for demographic and clinical parameters (e.g., age, sex).
Multiple measures of activity fragmentation significantly differed between pwMS and healthy controls, reflecting a more fragmented active behavior in pwMS. PwMS had a lower circadian rhythm amplitude, indicating a smaller amplitude in the circadian changes of daily activity, and weaker temporal correlations as based on the fractal analysis. When taking into account physical activity volume, one circadian amplitude measure and one fractal measure remained significantly different in pwMS and controls. Fragmentation measures and circadian amplitude measures were significantly associated with disability level as measured by the EDSS; the association with circadian amplitude remained significant, even after adjusting for the mean SVM.
The physical activity patterns of pwMS differ from those of healthy individuals in rest-activity fragmentation, the amplitude of the circadian rhythm, and fractal regulation. Measures describing these aspects of activity provide information that is not captured in the total volume of physical activity and could, perhaps, augment the monitoring of disease progression and evaluation of the response to interventions.
与健康对照者相比，多发性硬化症患者（pwMS）的身体活动水平较低。以往的研究主要集中在活动水平或活动量的研究上，但关于pwMS日常生活中休息 - 活动碎片化模式、昼夜节律和分形调节的研究有限。基于其他队列的研究结果，可以推测日常生活身体活动的这些方面将为pwMS的健康状况提供额外信息。因此，在此我们旨在：（1）确定pwMS与健康对照者之间在哪些碎片化、分形和昼夜节律幅度测量方面存在差异；（2）评估碎片化、分形和昼夜节律幅度测量与疾病严重程度之间的关系；（3）开始评估这些测量指标相对于更传统的身体活动测量指标（例如平均信号向量大小（SVM），一种身体活动总量的整体测量指标）的附加价值。
132例复发缓解型多发性硬化症患者（47±11岁，69.7%为女性，扩展残疾状态量表，EDSS，中位数（IQR）：3（2 - 4））和90例健康对照者（46±11岁，47.8%为女性）被要求在其下背部佩戴3D加速度计7天。提取休息 - 活动碎片化、昼夜节律幅度、分形调节和平均SVM指标。使用独立样本t检验和线性回归对pwMS和健康对照者进行比较，包括对平均SVM进行调整后的比较，以控制身体活动量的影响。使用测量指标之间的Spearman相关性和逻辑回归，基于在调整SVM后有显著差异的测量指标来识别临床状况。所有分析均对人口统计学和临床参数（例如年龄、性别）进行了调整。
pwMS与健康对照者在多个活动碎片化测量指标上存在显著差异，这反映出pwMS的活跃行为更加碎片化。pwMS的昼夜节律幅度较低，表明日常活动的昼夜变化幅度较小，并且基于分形分析的时间相关性较弱。在考虑身体活动量时，一个昼夜节律幅度测量指标和一个分形测量指标在pwMS和对照者之间仍存在显著差异。碎片化测量指标和昼夜节律幅度测量指标与EDSS测量的残疾水平显著相关；即使在调整平均SVM后，与昼夜节律幅度的相关性仍然显著。
pwMS的身体活动模式在休息 - 活动碎片化、昼夜节律幅度和分形调节方面与健康个体不同。描述这些活动方面的测量指标提供了身体活动总量中未涵盖的信息，并且可能有助于加强对疾病进展的监测和对干预反应的评估。
