Thyroid gland and sleep

A set of data suggests that the thyroid gland plays a role in the bi-direct ional interaction between the electrophysiological and the endocrine compon ents of sleep, e.g. the nonREM-REM-cycle and the patterns of nocturnal horm one secretion, respectively. In detail thyroid-stimulating hormone (TSH) an d thyroxin (T4) show circadian rhythms. A specific relationship was observe d between TSH and REM sleep. Blunted TSH levels were found in healthy elder ly subjects and, probably due to overactivity of corticotropin-releasing ho rmone in patients with depression in comparison to young normal controls. P ulsatile administration of thyrotropin-releasing hormone induced a decrease of sleep efficiency and an earlier occurrence of the cortisol rise in norm al controls. Slow wave sleep was reduced in patients with hypothyroidism in comparison to normal controls. The sleep EEG normalised after therapy.