[Cardiovascular symptoms and risks of subclinical dysthyroidism].
OBJECTIVE
To clarify the importance of cardiovascular symptoms and risks in subclinical dysthyroidism in order to define the best way of treatment and follow-up.


BACKGROUND
Subclinical dysthyroidism is defined by abnormal circulating TSH values in face and normal free thyroid hormones levels, in asymptomatic individuals. If the cardiovascular effects of overt hyperthyroidism are well documented, the relation between subclinical dysthyroidism and the heart is not well established. Subclinical hyperthyroidism may be caused by the same thyroid disorders that results in overt hyperthyroidism, but the most common cause is excessive dosage in levothyroxine. The most frequent cardias complication of subclinical hyperthyroidism is atrial fibrillation. Recently minimal alterations of myocardial function have also been described. In most patients, one tries to return to euthyroidism in order to prevent cardiovascular complications. Subclinical hypothyroidism is 3 to 10 times more frequent, especially in women after 60 years. Subtle modifications of cardiac function and lipid metabolism and an increased risk of atherosclerosis have been described in this condition. There is still debate about the decision to treat or not to treat these patients.


CONCLUSIONS
Until now, treatment of subclinical dysthyroidism is mainly based upon experiences and convictions to physicians. Prospective studies are necessary to assess the true benefits and risks of either early treatment or therapeutic abstention with regular clinical and biological follow up. In such studies, patients should be separated according to age and the nature (endogenous or exogenous) of dysthyroidism.
Arrivie
J
J
Service d'endocrinologie, maladies métaboliques et nutrition, centre hospitalier universitaire Nord, assistance publique des hôpitaux de Marseille, France.
Sbragia
P
P
Denizot
A
A
Paganelli
F
F
Oliver
C
C
D002318:Cardiovascular Diseases / Q000209:etiology*; D002320:Cardiovascular Physiological Phenomena; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications / Q000453:epidemiology / Q000209:etiology; D012307:Risk Factors; D013959:Thyroid Diseases / Q000150:complications*; D013963:Thyroid Hormones / Q000502:physiology
D013963:Thyroid Hormones