[Secretion of thyrotropin during states of wakefulness and sleep. Physiological data and clinical applications]

Abstract

Rhythmic hormone secretion appears to be a common characteristic of several endocrine systems. Alterations in these secretions are associated with the pathophysiology of certain diseases. Thyrotropin (TSH) exhibits a nocturnal surge in normal subjects. The time and the amplitude of the surge depend on the waking or the sleeping state. The TSH surge is decreased or abolished in various pathological conditions. Assessment of the surge is of particular interest for the early detection of central (pituitary) hypothyroidism, and in the exploration of isolated decreased TSH to predict further evolution toward hyperthyroidism. However, the characterization of the TSH surge needs simplification and standardization before this index could be used for the practical evaluation of thyroid function.