Circadian rhythms of thyroid hormones in patients with ischemic heart disease, arterial hypertension, and atrial fibrillation

Abstract

Aim. To evaluate the interrelationship between diurnal changes in thyrotropic hormone (TTH), free triiodothyronine (FT3), and clinical features of IHD in combination with AH and atrial fibrillation (AF). Materials and methods. Levels of TTH, FT3, and plasma cortisol were measured in 133 patients with IHD and AH with or without paroxysmal AF. The studied indexes included duration of IHD, AH, and AF; presence or absence of AF and AH; incidence rate of AF episodes per week; severity of exertional angina; systolic and diastolic BP; and EchoCG data. Results. Morning and evening TTH levels were significantly different and reached high values in the morning and low values in the evening in most patients (n=91; 68.4%). A part of patients (n=42; 31.6%) showed an opposite tendency with high TTH values in the evening, i.e., inversion of the TTH fluctuations. Such patients more often had a history of myocardial infarction, a high class of exertional angina, and recurrence of paroxysmal AF. Patients with the TTH inversion had a shorter AH duration but somewhat higher BP. Conclusion. A part of IHD patients had inversed TTH circadian changes associated with more severe clinical manifestations of cardiovascular pathology.

On the potential effect of circadian rhythms of cardiac troponins on the diagnosis of acute myocardial infarction

“…Along with the biorhythms that determine the performance of the organism functions (for example, the rhythm of sleep/wakefulness, blood pressure (BP) fluctuations, heart rate (HR), etc. ), there exist so-called regulatory biorhythms, in particular, circadian rhythms of hormone secretion [18,19]. To date, it has been established that most hormones (metabolism regulators) and metabolites, affected by the aforesaid regulators, have diurnal concentration variations, which should be considered in a study (selecting the time of biomaterial sampling) and interpreting the results.…”

“…Yu. Tsareva and colleagues reported on the existence of circadian rhythms of thyroid hormones and cortisol (in most patients morning concentrations are higher than in the evening hours), which is associated with a more severe clinical picture of CVD [19]. Thyroid hormones are known to potentiate the effect of catecholamines on the heart, increasing heart rate.…”

“…Considering the work of Yu. Tsareva et al (which states that cortisol concentrations are higher in the morning) [19] and the study by A Lazzarino et al (where cortisol values are shown to be associated with hs-cTnT levels) [13], it can be assumed that cortisol is also one of the important factors contributing to circadian (diurnal) differences in hs-cTnT concentration in patients.…”

Circadian rhythms of cardiac troponins: mechanisms and clinical significance

“…Активность клеток тиротропоцитов передней доли гипофиза повышается утром, что приводит к повышению уровня тиреотропного гормона, который, в свою очередь, активирует фолликулярные клетки щитовидной железы для выработки Т3 и Т4. Отмечено, что утром концентрация Т3 и Т4 в сыворотке крови пациентов превышает аналогичные вечерние показатели [43,44]. При этом более высокие уровни тиреоидных гормонов утром связаны с более тяжелой клинической картиной ССЗ (ишемической болезни сердца, артериальной гипертензии и фибрилляции предсердий) у этих пациентов [43,44].…”

“…Отмечено, что утром концентрация Т3 и Т4 в сыворотке крови пациентов превышает аналогичные вечерние показатели [43,44]. При этом более высокие уровни тиреоидных гормонов утром связаны с более тяжелой клинической картиной ССЗ (ишемической болезни сердца, артериальной гипертензии и фибрилляции предсердий) у этих пациентов [43,44]. Повышение уровня тиреоидных гормонов приводит к повышению ЧСС, и, как следствие, нарушению равновесия между потребностью и доставкой кислорода, что, по всей видимости, является причиной ЦР СТ (более высокой утренней концентрации СТ).…”