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[Changes of thyroid hormone levels in the progression of coronary arteriosclerosis]

I L Telkova, A T Tepliakov

    Klinicheskaia Meditsina
    |May 29, 2004
    PubMed

    Insights

    Thyroid hormone levels in ischemic heart disease patients change with disease severity. Before myocardial infarction, T4 to T3 conversion is inhibited; after infarction, hormone levels decrease, reflecting metabolic changes.

    Area of Science:

    • Cardiology
    • Endocrinology
    • Metabolic Research

    Background:

    • Ischemic heart disease (IHD) impacts cardiovascular and metabolic functions.
    • Thyroid hormones (TH), including thyroxine (T4) and triiodothyronine (T3), play a crucial role in regulating metabolism.
    • The relationship between IHD severity and thyroid hormone dynamics is not fully understood.

    Purpose of the Study:

    • To investigate changes in thyroid hormone (T3, T4) levels and their ratios in patients with ischemic heart disease (IHD).
    • To correlate these hormonal changes with the severity of coronary atherosclerosis, myocardial insufficiency, and clinical symptoms.
    • To compare thyroid hormone profiles with hemodynamic and metabolic parameters of the myocardium.

    Main Methods:

    • Serum levels of T3 and T4 were measured in patients with varying degrees of IHD, including incipient angina pectoris (IAP), acute myocardial infarction (AMI), and postinfarction myocardial dysfunction (PIMD).
    • Coronary atherosclerosis severity was assessed using coronaroangiography.
    • Thyroid hormone levels were analyzed in relation to hemodynamic and myocardial metabolic parameters.

    Main Results:

    • Thyroid hormone concentrations were found to be dependent on coronary circulation efficiency and myocardial metabolism.
    • In IHD patients before myocardial infarction (MI), thyroid hormone levels were stable, with inhibited conversion of T4 to T3.
    • Following MI and development of postinfarction myocardial dysfunction (PIMD), both T4 and T3 levels decreased below control levels, indicating altered myocardial metabolic processes.
    • In cases of intact myocardial function, the T4/T3 ratio was elevated due to high serum T4.
    • During acute coronary syndrome, T3 levels dropped while T4 levels increased, attributed to suppressed deiodination.

    Conclusions:

    • Thyroid hormone levels and their interconversion are significantly altered in patients with ischemic heart disease.
    • These alterations correlate with the severity of coronary atherosclerosis and myocardial dysfunction.
    • Changes in thyroid hormone metabolism reflect the intensity and pattern of metabolic processes within the myocardium during IHD progression and post-MI recovery.

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