Title: | Circulating cardiac troponin T exhibits a diurnal rhythm. |
Author(s): | Klinkenberg, L.J. ; Dijk, J.W. van ; Tan, F.E. ; Loon, L.J.C. van ; Dieijen-Visser, M.P. van ; Meex, S.J. |
Publication year: | 2014 |
Source: | Journal of the American College of Cardiology, vol. 63, iss. 17, (2014), pp. 1788-1795 |
ISSN: | 0735-1097 |
DOI: | https://doi.org/10.1016/j.jacc.2014.01.040 |
Publication type: | Article / Letter to editor |
Please use this identifier to cite or link to this item : https://hdl.handle.net/20.500.12470/2358 ![]() |
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Lectorate : | Sport en Voeding |
Journal title : | Journal of the American College of Cardiology |
Volume : | vol. 63 |
Issue : | iss. 17 |
Page start : | p.1788 |
Page end : | p.1795 |
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).
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