[Latent hypothyroidism--a minor laboratory variation or a disease?].

Latent hypothyreosis is a state which is characteristic by normal values of thyroid hormones (T3, T4) and moderately increased values of thyroid-stimulating hormone (TSH), or extensive response of TSH after stimulation with thyrotrophin-releasing hormone (TRH-test). The characteristic symptoms include goitre, symptoms of mammary glands (galactorrhea, benign mammary dysplasia), impairment of menstruation cycle and fertility and psychic disturbances (depressive symptomatology, deterioration of memory). The characteristic laboratory alterations include increased basal or stimulated values of prolactin and impairment of lipoprotein metabolism (significant decrease of HDL, increase of LDL). This aspect often makes the indication of substitution therapy justified in spite of normal concentrations of peripheral hormones. (Ref. 26).