S Jóhönnuson Elvar M, Sennels Henriette P, Jørgensen Henrik L, Hannibal Jens, Yeung Ching-Yan Chloé, Rasmussen Christine, Prus Gabriela Zofia, Wewer Albrechtsen Nicolai J, Nielsen Annelaura Bach
Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg, Nielsine Nielsens Vej 4B, Copenhagen, Denmark.
Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Clin Proteomics. 2025 Aug 22;22(1):29. doi: 10.1186/s12014-025-09551-7.
Plasma is the most used clinical specimen, yet diurnal variation in plasma proteins remains largely unexplored. We aimed to identify diurnally-regulated proteins in healthy individuals and assess their potential diagnostic implications, and highlight how diurnal awareness can advance future biomarker research.
Twenty-four healthy young individuals were studied under highly controlled conditions. Venous blood was drawn every three hours over a 24-h period, yielding 216 samples, of which 208 high-quality plasma samples were analyzed via high-throughput mass spectrometry. The missing data were filtered and imputed, and rhythmicity was assessed using Cosinor-based modeling with Benjamini-Hochberg correction. Tissue and pathway enrichment analyses were performed using the DAVID functional annotation tool.
Of 523 proteins that passed quality thresholds, 138 (~ 26%) exhibited significant diurnal oscillations. Tissue enrichment analysis revealed that most rhythmic proteins originated from the liver and platelets, with additional enrichment in a variety of tissue types. Pathway enrichment showed diurnal regulation of hemostasis, immune signaling, integrin-mediated processes, glucose metabolism, and protein synthesis. Notably, 36 clinically utilized biomarkers, including albumin, amylase, and cystatin C exhibited diurnal variation, suggesting that failing to account for temporal fluctuations may reduce diagnostic precision.
These findings demonstrate that over one-quarter of the human plasma proteome is under diurnal control. Such oscillations might have direct clinical implications, as the time-of-day may alter biomarker accuracy. Incorporating diurnal timing into diagnostic and research protocols, through standardized sampling or time-sensitive reference intervals, could improve patient care and inform future biomarker discoveries. Further research in larger, more diverse populations is needed to generalize these results and streamline practices in a way that takes diurnal variation into account.
血浆是最常用的临床样本，但血浆蛋白的昼夜变化在很大程度上仍未得到充分研究。我们旨在识别健康个体中受昼夜调节的蛋白质，评估其潜在的诊断意义，并强调昼夜意识如何推动未来的生物标志物研究。
在高度受控的条件下对24名健康年轻个体进行了研究。在24小时内每三小时采集一次静脉血，共获得216个样本，其中208个高质量血浆样本通过高通量质谱分析。对缺失数据进行过滤和插补，并使用基于余弦法的模型进行节律性评估，并采用Benjamini-Hochberg校正。使用DAVID功能注释工具进行组织和通路富集分析。
在523种通过质量阈值的蛋白质中，138种（约26%）表现出显著的昼夜振荡。组织富集分析表明，大多数有节律的蛋白质起源于肝脏和血小板，在多种组织类型中也有额外的富集。通路富集显示了止血、免疫信号、整合素介导的过程、葡萄糖代谢和蛋白质合成的昼夜调节。值得注意的是，36种临床使用的生物标志物，包括白蛋白、淀粉酶和胱抑素C表现出昼夜变化，这表明未能考虑时间波动可能会降低诊断准确性。
这些发现表明，超过四分之一的人类血浆蛋白质组受昼夜控制。这种振荡可能具有直接的临床意义，因为一天中的时间可能会改变生物标志物的准确性。通过标准化采样或时间敏感的参考区间将昼夜时间纳入诊断和研究方案中，可以改善患者护理并为未来的生物标志物发现提供信息。需要在更大、更多样化的人群中进行进一步研究，以推广这些结果，并以考虑昼夜变化的方式简化实践。
