Adriaanse R, Romijn J A, Endert E, Wiersinga W M
Department of Endocrinology, Academic Medical Centre, University of Amsterdam, The Netherlands.
Acta Endocrinol (Copenh). 1992 Mar;126(3):206-12. doi: 10.1530/acta.0.1260206.
The nocturnal TSH surge was studied in controls, in 34 patients with hypothalamic/pituitary disease and in 21 patients with primary hypothyroidism. It was absent in 5/12 hypothyroid patients and in 5/22 euthyroid patients with hypothalamic/pituitary disease (42% vs 23%, NS). Central hypothyroidism relative to euthyroidism was associated with a lower absolute (0.3 +/- 0.4 vs 0.9 +/- 1.0 mU/l, p less than 0.05) and relative (24 +/- 31 vs 63 +/- 51%, p less than 0.05) nocturnal rise in TSH. In primary hypothyroidism, the nocturnal TSH surge was absent in eight of ten patients with overt, in one of five patients with mild and in none of six patients with subclinical hypothyroidism. The relative nocturnal rise in TSH was normal in mild (54 +/- 33%) and subclinical (92 +/- 69%), but decreased in overt hypothyroidism (2 +/- 10%). Plasma T4 was positively and 09.00 plasma TSH negatively related to the relative nocturnal TSH surge in primary hypothyroidism, but not in central lesions. In both conditions, however, a positive relationship was observed between the relative nocturnal TSH surge and the relative increase of TSH to TRH.
(a) The nocturnal TSH surge is usually absent in overt hypothyroidism but present in mild primary hypothyroidism and equivocal in central hypothyroidism. This limits its usefulness as an adjunct in the diagnosis of central hypothyroidism. (b) The magnitude of the nocturnal TSH surge in patients with hypothalamic/pituitary disease or primary hypothyroidism is directly related to the TSH response to TRH, and thus appears to be determined by the directly releasable TSH pool of the pituitary.
对正常对照组、34例下丘脑/垂体疾病患者及21例原发性甲状腺功能减退患者的夜间促甲状腺激素（TSH）高峰进行了研究。12例甲状腺功能减退患者中有5例以及22例下丘脑/垂体疾病的甲状腺功能正常患者中有5例未出现夜间TSH高峰（42%对23%，无显著性差异）。相对于甲状腺功能正常，中枢性甲状腺功能减退与较低的夜间TSH绝对升高幅度（0.3±0.4对0.9±1.0 mU/L，p<0.05）及相对升高幅度（24±31%对63±51%，p<0.05）相关。在原发性甲状腺功能减退中，10例显性患者中有8例、5例轻度患者中有1例以及6例亚临床甲状腺功能减退患者中无一例出现夜间TSH高峰。轻度（54±33%）和亚临床（92±69%）甲状腺功能减退患者的夜间TSH相对升高幅度正常，但显性甲状腺功能减退患者降低（2±10%）。在原发性甲状腺功能减退中，血浆T4与夜间TSH相对高峰呈正相关，09:00的血浆TSH与夜间TSH相对高峰呈负相关，但在中枢性病变中并非如此。然而，在这两种情况下，夜间TSH相对高峰与TSH对促甲状腺激素释放激素（TRH）的相对升高之间均存在正相关。
（a）显性甲状腺功能减退患者通常无夜间TSH高峰，轻度原发性甲状腺功能减退患者存在夜间TSH高峰，而中枢性甲状腺功能减退患者的夜间TSH高峰不明确。这限制了其作为中枢性甲状腺功能减退诊断辅助手段的作用。（b）下丘脑/垂体疾病或原发性甲状腺功能减退患者夜间TSH高峰的幅度与TSH对TRH的反应直接相关，因此似乎由垂体中可直接释放的TSH储备决定。
