Thyrotropin secretion in mild and severe primary hypothyroidism is distinguished by amplified burst mass and Basal secretion with increased spikiness and approximate entropy.

Context: Twenty-four-hour TSH secretion profiles in primary hypothyroidism have been analyzed with methods no longer in use. The insights afforded by earlier methods are limited.

Objective: We studied TSH secretion in patients with primary hypothyroidism (eight patients with severe and eight patients with mild hypothyroidism) with up-to-date analytical tools and compared the results with outcomes in 38 healthy controls.

Thyrotropin secretion profiles are not different in men and women.

Context: The hypothalamo-pituitary-thyroid axis in women may differ from that in men. Previous reports have shown an almost 2-fold increased response to TRH in females compared with males.

Objective: We analyzed TSH profiles in healthy men and women to delineate differences in the hypothalamo-pituitary-thyroid system.