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Circulating cardiac troponin T exhibits a diurnal rhythm
Klinkenberg, Lieke J. J. van Dijk, Jan-Willem Tan, Frans E. S. van Loon, Luc J.C. van Dieijen-Visser, Marja P. Meex, Steven J. R.
Klinkenberg, Lieke J. J.
van Dijk, Jan-Willem
Tan, Frans E. S.
van Loon, Luc J.C.
van Dieijen-Visser, Marja P.
Meex, Steven J. R.
Abstract
Objectives The goal of this study was to test the unverified assumption that chronically elevated cardiac troponin T (cTnT) levels fluctuate randomly around a homeostatic set point. Background The introduction of high-sensitivity cardiac troponin (cTn) assays has improved sensitivity for acute myocardial infarction (AMI). However, many patients with a single positive cTn test result do not have AMI. Therefore, the diagnosis of AMI relies strongly on serial testing and interpretation of cTn kinetics. Essential in this regard is a profound understanding of the biological variation of cTn. Methods Two studies were conducted to assess biological cTnT variation and to investigate the presence of a diurnal rhythm of cTnT. Study 1 comprised 23 male subjects with type 2 diabetes, with no acute cardiovascular disease. Serial venous blood samples were drawn over an 11-h period (8:30 AM to 7:30 PM). In study 2, the presence of a diurnal cTnT rhythm was investigated by hourly sampling of 7 subjects from study 1 over 25 h. Results In study 1, we observed a gradual decrease in cTnT concentrations during the day (24 2%). This decrease was present in all participants and was most prominent in subjects with the highest baseline cTnT values (Pearson’s R 0.93). Diurnal variation of cTnT, as assessed in study 2, was characterized by peak concentrations during morning hours (8:30 AM, 17.1 2.9 ng/l), gradually decreasing values during daytime (8:30 PM, 11.9 1.6 ng/l), and rising concentrations during nighttime (8:30 AM the next day, 16.9 2.8 ng/l). Conclusions A diurnal cTnT rhythm substantiates the recommendation that all dynamic changes in cTnT should be interpreted in relation to the clinical presentation. Epidemiological studies and risk-stratification protocols with the use of cTnT may benefit from standardized sampling times. (Exercise and Glycemic Control in Type 2 Diabetes; NCT00945165) (J Am Coll Cardiol 2014;63:1788–95) ª 2014 by the American College of Cardiology Foundation Ca
Keywords
biological variation, cardiac troponin, diurnal rhythm
Date
2014
Type
Journal article
Journal
Journal of the American College of Cardiology
Book
Volume
63
Issue
17
Page Range
1788-1795
Article Number
ACU Department
Collections
Relation URI
Source URL
Event URL
Open Access Status
Open access
License
File Access
Controlled