背景:先前的移动健康(mHealth)研究表明,抑郁症与通过可穿戴设备测量的昼夜节律特征之间存在显着联系。然而,这些研究没有充分考虑季节性变化的综合影响,在现实世界中的潜在偏见解释。
目的:本研究旨在探讨抑郁症严重程度与可穿戴测量的昼夜节律之间的关联,同时考虑季节性影响。
方法:数据来自一项大型纵向mHealth研究,其中使用8项患者健康问卷(PHQ-8)每两周评估参与者的抑郁严重程度,和参与者的行为,包括睡眠,步数,心率(HR),通过Fitbit设备跟踪长达2年。我们从每次PHQ-8评估之前的14天Fitbit数据中提取了12个昼夜节律特征,包括余弦变量,如HR峰值定时(HR顶相),和非参数特征,例如最活跃的连续10小时期(M10发作)的发作。为了调查抑郁症严重程度与昼夜节律之间的关系,同时评估季节性影响,我们为每个昼夜节律特征使用了三个嵌套的线性混合效应模型:(1)将PHQ-8评分作为自变量,(2)增加季节性,和(3)在季节和PHQ-8得分之间添加相互作用项。
结果:分析来自543名参与者的10,018个PHQ-8记录以及Fitbit数据(n=414,76.2%为女性;平均年龄48,IQR32-58岁),我们发现,在调整了季节性影响后,较高的PHQ-8评分与每日步数减少相关(β=-93.61,P<.001),睡眠变异性增加(β=0.96,P<.001),和延迟的昼夜节律(即,睡眠开始:β=0.55,P=.001;睡眠偏移:β=1.12,P<.001;M10开始:β=0.73,P=.003;HR顶期:β=0.71,P=.001)。值得注意的是,与冬季相比,春季(PHQ-8×spring的β=-31.51,P=.002)和夏季(PHQ-8×summer的β=-42.61,P<.001)与日步数的负相关更为明显。此外,仅在夏季观察到与M10延迟发作的显着相关性(PHQ-8×summer=1.06,P=.008)。此外,与冬天相比,参与者的睡眠时间缩短了16.6分钟,每日步数增加394.5,M10发作延迟20.5分钟,夏季HR高峰时间延迟67.9分钟。
结论:我们的研究结果强调了季节性对人类昼夜节律的显著影响及其与抑郁症的关系,强调在实际应用中考虑mHealth研究中季节性变化的重要性。这项研究还表明,可穿戴测量的昼夜节律作为抑郁症的数字生物标志物的潜力。
BACKGROUND: Previous mobile health (mHealth) studies have revealed significant links between depression and circadian rhythm features measured via wearables. However, the comprehensive impact of seasonal variations was not fully considered in these studies, potentially biasing interpretations in real-world settings.
OBJECTIVE: This study aims to explore the associations between depression severity and wearable-measured circadian rhythms while accounting for seasonal impacts.
METHODS: Data were sourced from a large longitudinal mHealth study, wherein participants\' depression severity was assessed biweekly using the 8-item Patient Health Questionnaire (PHQ-8), and participants\' behaviors, including sleep, step count, and heart rate (HR), were tracked via Fitbit devices for up to 2 years. We extracted 12 circadian rhythm features from the 14-day Fitbit data preceding each PHQ-8 assessment, including cosinor variables, such as HR peak timing (HR acrophase), and nonparametric features, such as the onset of the most active continuous 10-hour period (M10 onset). To investigate the association between depression severity and circadian rhythms while also assessing the seasonal impacts, we used three nested linear mixed-effects models for each circadian rhythm feature: (1) incorporating the PHQ-8 score as an independent variable, (2) adding seasonality, and (3) adding an interaction term between season and the PHQ-8 score.
RESULTS: Analyzing 10,018 PHQ-8 records alongside Fitbit data from 543 participants (n=414, 76.2% female; median age 48, IQR 32-58 years), we found that after adjusting for seasonal effects, higher PHQ-8 scores were associated with reduced daily steps (β=-93.61, P<.001), increased sleep variability (β=0.96, P<.001), and delayed circadian rhythms (ie, sleep onset: β=0.55, P=.001; sleep offset: β=1.12, P<.001; M10 onset: β=0.73, P=.003; HR acrophase: β=0.71, P=.001). Notably, the negative association with daily steps was more pronounced in spring (β of PHQ-8 × spring = -31.51, P=.002) and summer (β of PHQ-8 × summer = -42.61, P<.001) compared with winter. Additionally, the significant correlation with delayed M10 onset was observed solely in summer (β of PHQ-8 × summer = 1.06, P=.008). Moreover, compared with winter, participants experienced a shorter sleep duration by 16.6 minutes, an increase in daily steps by 394.5, a delay in M10 onset by 20.5 minutes, and a delay in HR peak time by 67.9 minutes during summer.
CONCLUSIONS: Our findings highlight significant seasonal influences on human circadian rhythms and their associations with depression, underscoring the importance of considering seasonal variations in mHealth research for real-world applications. This study also indicates the potential of wearable-measured circadian rhythms as digital biomarkers for depression.