Longo-Silva Giovana, Serenini Renan, Antunes Roberto, Lima Márcia, Pedrosa Anny, Menezes Risia
Research Group 'Chronobiology, Nutrition and Health' of Federal University of Alagoas, Maceió, Alagoas, Brazil.
Faculty of Economics, Sapienza University of Rome, Rome, Italy.
Sleep Med X. 2024 Dec 20;9:100137. doi: 10.1016/j.sleepx.2024.100137. eCollection 2025 Dec.
To examine the influence of latitude, longitude, sunrise, and daylight, in conjunction with individual and behavioral factors, on sleep duration, wake time, and bedtime in a country with the world's broadest latitude range, yet characterized by homogeneity in language, cultural traits, and consistent time zones.
Participants (n = 1440; 18-65y) were part of a virtual population-based survey (2021-22). Sleep patterns were spatially represented through maps using Multilevel B-spline Interpolation. Relationships between and within biological/personal/socio-economic, behavioral and environment characteristics, and sleep outcomes were examined by Lasso regression. Restricted cubic splines were employed to examine the shape of the association of latitude and sunrise with sleep variables and of screen time before bed with bedtime.
Latitude emerged as the primary geographic factor influencing variations in sleep duration and wake time, shortening and advancing, respectively, as latitude increased (towards equatorial line). Younger individuals, those living without partners, with depression, engaging in more frequent evening alcohol consumption, and with poorer diet quality, tended to wake up later. All the variables influenced bedtime, with daylight emerging as the environmental factor exerting the strongest association. While the variability in bedtime showed a non-linear association with latitude and sunrise, it displayed a dose-response relationship with screen time before bed.
Given that adults living in the same country, potentially with a similar timetable, could be having shorter sleep durations according to their latitude position, further studies are required to contemplate advocating for policies that implement schedules based on the sun position rather than the national time zone.
在一个拥有世界上最广泛纬度范围、但语言、文化特征和时区一致的国家，研究纬度、经度、日出和日照时间，以及个体和行为因素对睡眠时间、起床时间和就寝时间的影响。
参与者（n = 1440；18 - 65岁）是一项基于虚拟人群的调查（2021 - 2022年）的一部分。睡眠模式通过使用多层B样条插值的地图进行空间表示。通过套索回归研究生物/个人/社会经济、行为和环境特征之间以及内部与睡眠结果之间的关系。使用受限立方样条来研究纬度和日出与睡眠变量的关联形状，以及睡前屏幕时间与就寝时间的关联形状。
纬度成为影响睡眠时间和起床时间变化的主要地理因素，随着纬度增加（向赤道线方向），睡眠时间缩短，起床时间提前。较年轻的个体、没有伴侣生活的人、患有抑郁症的人、晚上饮酒更频繁的人以及饮食质量较差的人往往起床较晚。所有变量都影响就寝时间，日照时间成为与之关联最强的环境因素。虽然就寝时间的变异性与纬度和日出呈非线性关联，但与睡前屏幕时间呈剂量反应关系。
鉴于生活在同一国家的成年人，可能有相似的时间表，但根据其纬度位置睡眠时间可能较短，需要进一步研究考虑倡导实施基于太阳位置而非国家时区的时间表政策。
