Plasma concentrations of cardiac troponins, the preferred biomarkers for the diagnosis of acute myocardial infarction, are often persistently elevated in patients with chronic kidney disease (CKD). The origin of these elevations is unknown: Is it the heart, by increased release, or the kidneys, by decreased renal elimination? In clinical practice, this equivocal view on troponin elevations in patients with reduced glomerular clearance underlies countless clinical discussions among physicians and may delay rapid initiation of adequate treatment when these patients present with chest pain.

In the present study, we aimed to discriminate between increased cardiac release and reduced renal elimination as the main process underlying this phenomenon. Specifically, we used the recently demonstrated rhythmic diurnal oscillation pattern of troponin T as a model to assess the contribution of impaired renal elimination to persistently elevated cardiac troponin levels in patients with CKD.¹ The diurnal troponin T rhythm is characterized by gradually decreasing concentrations throughout daytime and rising concentrations during nighttime.¹ If decreased renal clearance, and not increased production, is the key driver of elevated troponins in patients with CKD, the increased half-life and subsequent accumulation of cardiac troponin T will fade its diurnal rhythm. …

慢性肌钙蛋白（诊断急性心肌梗死的首选生物标志物）的血浆浓度在患有慢性肾脏病（CKD）的患者中经常持续升高。这些升高的起因尚不清楚：是由于释放增加而引起的心脏，还是由于肾脏消除减少而导致的肾脏？在临床实践中，对于肾小球清除率降低的患者肌钙蛋白升高的这种模棱两可的观点是医生之间无数临床讨论的基础，并且当这些患者出现胸痛时可能会延迟快速开始适当的治疗。

在本研究中，我们旨在区分增加的心脏释放和减少的肾脏消除，这是造成这种现象的主要过程。具体而言，我们使用了最近证实的肌钙蛋白T的节律性昼夜振荡模式作为模型，以评估CKD患者肾脏消除功能受损对持续升高的心肌肌钙蛋白水平的影响。¹日性肌钙蛋白T节律的特征是白天逐渐降低浓度，夜间逐渐升高浓度。¹如果CKD患者肌钙蛋白升高的关键驱动因素是肾清除率降低而不是产量增加，则其半衰期延长和随后心肌肌钙蛋白T的积累将使其昼夜节律消失。…