[Plasma noradrenaline in hyperthyroidism and hypothyroidism]. / Noradrénaline plasmatique dans l'hyperthyroïdie et l'hypothyroïdie.

Plasma noradrenaline concentrations (NA) were measured in 11 hypothyroid patients, 24 hypothyroid patients and 30 normal subjects after 30 minutes of supine rest and after 5 minutes of standing. Observed noradrenaline levels, after rest as well as after standing, were significantly higher in hypothyroid patients (NA rest = 0.66 +/- 0.35 microgram/l, NA standing = 1.26 +/- 0.70 micrograms/l) and significantly lower in hyperthyroid patients (NA rest = 0.22 +/- 0.13 micrograms/l, NA standing = 0.37 +/- 0.20 microgram/l) than in normal subjects (NA rest = 0.32 +/- 0.13 microgram/l, NA standing = 0.55 +/- 0.20 microgram/l). The increase in noradrenaline with standing, when expressed in percent, was similar for the three groups studied (about 100%). These results suggest that a sympathetic nervous system adaptation occurs in hyperthyroidism and hypothyroidism as a compensatory phenomenon to the direct effect of thyroid hormones on the heart.

[Non-tumor-related hirsutism in the adult woman: ovarian dystrophy or disorders of adrenal gland hormonogenesis?]. / Hirsutismes non tumoraux de la femme adulte: dystrophie ovarienne ou trouble de l'hormonogénèse surrénalienne?

As Yen admits, polycystic ovarian disease (POD) probably has several causes, one of which involves an adrenal origin. In 20 out of a group of 45 hirsute women, the authors detected a biologic pattern suggesting ovarian dystrophy. Kinetic investigation of the adrenal function in these subjects during a synacthen retard test detected abnormal adrenal hormone production due to partial enzymatic block: in 3 cases of 21-hydroxylase, in 1 case of 11-hydroxylase and in 3 cases of 3 beta-hydroxydehydrogenase. The existence of the first two types of blockade is well established, but that of the third type remains subject to doubt. Systematic screening for disorders of this type during ovarian dystrophy would appear to be of clinical interest. The frequently empirical prescription of dexamethasone in dysovulation in POD cases may find its justification in this phenomenon; the same is also true for the use of bromocriptine in 3 beta-hydroxydehydrogenase.

[Assay of the free fraction of thyroxine. Its role in the study of thyroid function]. / Dosage de la fraction libre de la thyroxine. Sa place dans l'exploration fonctionnelle thyroïdienne.

In a prospective study of 467 subjects with normal, increased or decreased thyroid function the results of free thyroxine (FT4) assays by 2 radioimmunological methods were compared with the free thyroxine index (FT1) and the T4/TBG ratio. It appeared from this study that FT4 assays were at least as good as the FT1 to confirm the diagnosis of euthyroidism and were distinctly superior to measurements of FT1, T4 adn T3 in patients with abnormal thyroid function. In view of the close correlation observed between clinical findings and the results of FT4 assays, a new strategy may be proposed to investigate thyroid function. However, further studies are required to evaluate the reliability of FT4 assays in some severe pathological conditions or in patients taking drugs interfering with thyroid hormone metabolism.

[Fruste form of hyperthyroidism manifested by auricular arrhythmia. Importance of the assay of the free fraction of thyroxine (FT4) and the role of the TRH test]. / Hyperthyroïdie fruste révélée par un trouble du rythme auriculaire. Intérêt du dosage de la fraction libre de la thyroxine (FT4) et place du test à la TRH.

The TRH test was used to detect hyperthyroidism in 87 patients aged from 38 to 85 years who presented with atrial arrhythmia with or without heart disease. The patients had no clinical evidence of thyrotoxicosis, and total thyroxine (T4), free thyroxine index (FTI) and triiodothyronine (T3) values were normal. Hyperthyroidism was diagnosed in the 18 patients (21%) with negative TRH test; 15 of them had high free thyroxine (FT4) levels. The most common causes of hyperthyroidism were "warm" nodules in 7 and iodine overload in 10. Adding an anti-thyroid treatment to the hitherto unsuccessful anti-arrhythmic treatment resulted in a return to sustained sinus rhythm in 50% of cases. FT4 levels became normal in all. This study indicates that all patients with atrial arrhythmia, with or without heart disease, should be investigated for occult hyperthyroidism. It also demonstrates the value of FT4 assays to detect the disease. The TRH test is only required as a second-line exploratory method in some patients, notably those with iodine overload.