Chronic fatigue syndrome: circadian rhythm and hypothalamic-pituitary-adrenal (HPA) axis impairment.

Chronic Fatigue Syndrome (CFS) is a clinical condition characterized by a persistent or relapsing debilitating fatigue at rest, lasting more than 6 months, and made worse by exercise. At the present moment, there are three potential etiopathogenic factors: immunologic, viral and neuroendocrine. The purpose of our study was to evaluate possible alterations of the hypothalamic-pituitary-adrenal (HPA) axis in our CFS patients by studying the circadian rhythms of prolactin (PRL), thyrotropic hormone (TSH), adrenocorticotropic hormone (ACTH), and cortisol (CS). A total of 36 patients were enrolled according to the Centers for Disease Control and Prevention case-definition criteria. Twenty healthy subjects were included as controls. Blood samples were taken every 4 hours during a single 24-hour period. We performed a fluorometric enzyme immunoassay with serum PRL, cortisol and TSH, and an immunoradiometric assay with plasma ACTH. The circadian rhythms of PRL, TSH, ACTH and CS were statistically significant in both CFS and control groups. At 24:00 and 04:00 hrs the CFS patients showed lower ACTH levels than healthy subjects (p < 0.001); the PRL levels were higher at 04.00 h in CFS patients than in healthy subjects.

[Autonomous adenoma of the thyroid]. / L'adenoma autonomo della tiroide.

Toxic goitre often referred to in the literature as "autonomous" adenoma or nodule actually signifies a number of different pathologies that are characterised by autonomy and hyperfunction so that it is now thought more appropriate to call it an autonomous follicle. Clinical features and the hormone profile suggest the diagnosis which is confirmed by scintiscan with curve as well as dynamic inhibition and stimulation tests using TRH, procedures that reveal both latent hyperfunction and autonomy. The most common current therapeutic approach is surgical since this provides a complete cure while leaving the surrounding thyroid tissue undisturbed.

[Circadian rhythm of temperature, heart rate and blood pressure in normal rats and hypothyroid rats]. / Ritmo circadiano della temperatura, della frequenza cardiaca, della pressione sanguigna in ratti normali e in ratti ipotiroidei.

We explored the circadian variation of core temperature, heart rate and blood pressure in hypothyroid and euthyroid male Sprague-Dawley rats. A circadian rhythm was quantified by the population mean-cosinor method for the core temperature of both hypothyroid and intact rats, whereas for the blood pressure and heart rate values a circadian rhythm was validated by rejection of the zero-amplitude assumption only in the hypothyroid rats. Whether hypothyroid rats adjust to new schedules at a rate different from euthyroid animals is an inference from these studies awaiting scrutiny.