Gubin Denis, Danilenko Konstantin, Stefani Oliver, Kolomeichuk Sergey, Markov Alexander, Petrov Ivan, Voronin Kirill, Mezhakova Marina, Borisenkov Mikhail, Shigabaeva Aislu, Yuzhakova Natalya, Lobkina Svetlana, Petrova Julianna, Malyugina Olga, Weinert Dietmar, Cornelissen Germaine
Department of Biology, Tyumen Medical University, Tyumen, Russia.
Laboratory for Chronobiology and Chronomedicine, Research, Institute of Biomedicine and Biomedical Technologies, Tyumen Medical University, Tyumen, Russia.
J Pineal Res. 2025 Jan;77(1):e70023. doi: 10.1111/jpi.70023.
Light environment in the Arctic differs widely with the seasons. Studies of relationships between objectively measured circadian phase and amplitude of light exposure and melatonin in community-dwelling Arctic residents are lacking. This investigation combines cross-sectional (n = 24-62) and longitudinal (n = 13-27) data from week-long actigraphy (with light sensor), 24-h salivary melatonin profiles, and proxies of metabolic health. Data were collected within the same week bracketing spring equinox (SE), and winter/summer solstices (WS/SS). Drastic seasonal differences in blue light exposure (BLE) corresponded to seasonal changes in the 24-h pattern of melatonin, which was phase delayed and reduced in normalized amplitude (NA) during WS/SS compared to SE. The extent of individual melatonin's acrophase and Dim Light Melatonin Onset (DLMO) change from SE to WS correlated with that from SE to SS. Although similar in extent and direction, melatonin phase changes versus SE were linked to morning BLE deficit in WS, contrasting to evening BLE excess in SS. Seasonal changes in sleep characteristics were closely associated with changes in the phases of BLE and melatonin. Proxies of metabolic health included triglycerides (TG), high-density lipoprotein cholesterol (HDL), TG/HDL ratio, and cortisol. Adverse seasonal changes in these proxies were associated with delayed acrophases of BLE and melatonin during WS and SS. TG and TG/HDL were higher in WS and SS than in SE, and cross-sectionally correlated with later melatonin and BLE acrophases, while lower HDL was associated with later BLE onset and later melatonin acrophase. Overall, this study shows that optimal 24-h patterns of light exposure during SE is associated with an earlier acrophase and a larger 24-h amplitude of melatonin, and that both features are linked to better metabolic health. Improving light hygiene, in particular correcting winter morning light deficit and summer evening light excess may help maintain metabolic health at high latitudes. Novel solutions for introducing proper circadian light hygiene such as human-centric light technologies should be investigated to address these issues in future studies.
北极地区的光照环境随季节变化差异很大。目前尚缺乏对北极地区社区居民客观测量的昼夜节律相位、光照暴露幅度与褪黑素之间关系的研究。本研究结合了为期一周的活动记录仪（带有光传感器）、24小时唾液褪黑素谱以及代谢健康指标的横断面（n = 24 - 62）和纵向（n = 13 - 27）数据。数据在春分（SE）以及冬至/夏至（WS/SS）所在的同一周内收集。蓝光暴露（BLE）的剧烈季节性差异与褪黑素24小时模式的季节性变化相对应，与SE相比，WS/SS期间褪黑素的相位延迟且标准化幅度（NA）降低。个体褪黑素峰值相位和暗光褪黑素起始（DLMO）从SE到WS的变化程度与从SE到SS的变化程度相关。尽管程度和方向相似，但与SE相比，褪黑素相位变化在WS中与早晨BLE不足相关，而在SS中与傍晚BLE过量形成对比。睡眠特征的季节性变化与BLE和褪黑素相位的变化密切相关。代谢健康指标包括甘油三酯（TG）、高密度脂蛋白胆固醇（HDL）、TG/HDL比值和皮质醇。这些指标的不利季节性变化与WS和SS期间BLE和褪黑素的峰值相位延迟有关。TG和TG/HDL在WS和SS中高于SE，并且在横断面上与较晚的褪黑素和BLE峰值相位相关，而较低的HDL与较晚的BLE起始和较晚的褪黑素峰值相位相关。总体而言，本研究表明，SE期间最佳的24小时光照模式与更早的峰值相位和更大的24小时褪黑素幅度相关，并且这两个特征都与更好的代谢健康相关。改善光照卫生，特别是纠正冬季早晨光照不足和夏季傍晚光照过量，可能有助于在高纬度地区维持代谢健康。未来研究应探索引入适当的昼夜节律光照卫生的新解决方案，如以人为本的照明技术，以解决这些问题。
