[Thyroid hormones and thyroid-stimulating hormone in patients with chronic heart failure--relationship between primary hypothyroidism with iodine organification defect and chronic heart failure].

Serum concentrations of triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) were measured in 127 patients with chronic heart failure (CHF) (left ventricular ejection fraction; 40% < or = and NYHA; III-IV), and 1,079 patients without CHF (non-CHF) (left ventricular ejection fraction; 40% < or = and NYHA; I-II). Serum-T3, T4 and free-T4 were significantly decreased in patients with CHF. The prevalence of slight increase of serum TSH (5 < or = TSH < 15 microU/ml) were 20.5% in CHF and 4.08% in non-CHF. There was a statistically significant difference in the prevalence of slight increase of TSH (p < 0.01). In the patients with slight increase of serum TSH, the 123I-thyroid scintigraphy and perchlorate test were performed 12 patients with CHF and 19 patients with non-CHF. The incidences of iodine organification defect were 33.3% in CHF and 5.26% in non-CHF. There was a statistically significant difference in the incidence of iodine organification defect (p < 0.05). The histologic examination of thyroid biopsy specimen obtained 12 patients with CHF and primary hypothyroidism, these revealed only non-specific mild atrophic changes. Follicular damage and lymphocyte-infiltration were not evident. These findings suggest that the primary hypothyroidism were frequently complicated in CHF and associated with iodine organification defect by reduction of thyroid-peroxidase activity or decrease of hydrogen peroxidase. We conclude that the primary hypothyroidism with iodine organification defect was probably developed as a result of CHF.