Circadian rhythms of cardiac troponins: mechanisms and clinical significance

Abstract

Modern laboratory methods for determining biomarkers of cardiovascular diseases are highly sensitive and can detect almost single molecules in human biological fluids, significantly speeding up and improving the diagnosis of cardiovascular diseases. However, in this case, there is a decrease in specificity and it is necessary to take into account a number of additional factors that may affect the result of the study. Recent studies have shown that circadian rhythms (CR) are among these factors. This review article is devoted to the discussion of recently discovered CR of cardiac troponins (CT). A number of articles reported that, both in healthy people and in patients with a number of chronic diseases, CT concentrations change during the day. Given that modern algorithms for diagnosing myocardial infarction (MI) are based on serial studies (0-1 h and 0-3 h) of blood serum, and the values of CT in the blood serum for the diagnosis of myocardial infarction (MI) for this period of time are only a few ng/l, the CT CR can to some extent affect the accuracy of MI diagnosis. Thus, natural physiological changes in the concentration of CT during the day can be mistakenly interpreted as diagnostically significant deviations and lead to an erroneous interpretation of laboratory test results.

Cardiac Troponins: Contemporary Biological Data and New Methods of Determination

“…60 Gender, age and circadian features provide quite remarkable information obtained by highly sensitive methods about the troponin biology. 61 With regard to gender characteristics, it was found that the level of cardiacspecific troponins in men is higher than in women, which is recommended to be used to determine the values of 99th percentile in modern diagnostic algorithms for the diagnosis of AMI. [62][63][64] The higher level of cardiac troponins in men is explained by the fact that they have a larger left ventricular mass than women.…”

“…70 It is noteworthy that circadian fluctuations of hs-cTnT concentrations are much more pronounced in patients with comorbid pathologies, in particular CRF and diabetes mellitus, than in healthy patients. 61 According to some reports, circadian rhythms may have a potential impact on the accuracy of early diagnosis of AMI and screening for CVD. 36 For example, hs-cTnI and hs-cTnT levels that naturally change throughout the day can be erroneously interpreted as diagnostically significant abnormalities.…”

“…111 This table presents current data obtained in a number of recent studies on the possible existence of circadian rhythms and age-related features in hs-cTnI and hs-cTnT content for some tests. 34,36,59,61,[67][68][69][70][105][106][107][108][109][110] As noted above, the influence of circadian and age-related features on the diagnosis of CVD and AMI is still poorly understood and requires further research and clarification of specific numerical indicators.…”

New biomarkers for cardiovascular risk stratification

“…Сердечно-сосудистые заболевания являются одними из ведущих причин смертности и инвалидизации населения. Лабораторная диагностика сердечнососудистых заболеваний является актуальным направлением, поскольку она является одним из ключевых методов верификации диагноза [1,2,3,4,5].…”

“…Изучение новых биомаркеров должно включать валидацию аналитической погрешности и пределов обнаружения, характеристику калибратора, специфичность и стандартизацию анализа, преаналитические вопросы и соответствующие исследования референсных интервалов [5,6,7,8,9,10]. Идеальный биомаркер должен помочь врачу в диагностике, прогнозе и лечении.…”