{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T18:36:11Z","timestamp":1777919771436,"version":"3.51.4"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2008,4,1]],"date-time":"2008-04-01T00:00:00Z","timestamp":1207008000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2008,4,1]],"date-time":"2008-04-01T00:00:00Z","timestamp":1207008000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Neuroendocrinology"],"abstract":"<jats:p>The aim of this study was to explore the occurrence of abnormalities in the circannual thyrotropin (TSH) rhythm in Klinefelter\u2019s syndrome (KS). For 3 years, 69 healthy adult males and 73 patients with KS, usually living in Sardinia, were studied by a cross-sectional design. Plasma samples were taken between 08.00 and 09.00 h and TSH was radioimmunoassayed. First, the mean (\u00b1 SD) of the data, grouped for each month of the year, was estimated to seek any macroscopic annual variation. Then, a cosine function was fitted to the single serially independent data by the single cosinor method in order to test for any statistically significant rhythm and, if the no-rhythm assumption is rejected, to describe the circannual parameters. Our patients showed circannual mean TSH concentrations lower than controls (p &lt; 0.001) without any statistically significant circannual rhythm, which was instead apparent in normal subjects with the annual crest time in December (95% CL November\u2013February). Our results support the hypothesis that in KS the impaired TSH secretion may be related to abnormalities in the hypothalamic-pituitary coordination of the circannual rhythmicity of this hormone.<\/jats:p>","DOI":"10.1159\/000124519","type":"journal-article","created":{"date-parts":[[2008,4,2]],"date-time":"2008-04-02T11:56:21Z","timestamp":1207137381000},"page":"132-134","source":"Crossref","is-referenced-by-count":7,"title":["Circannual Variations of Plasma Thyrotropin in Klinefelter\u2019s Syndrome"],"prefix":"10.1159","author":[{"given":"Antonio","family":"Bellastella","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tullio","family":"Criscuolo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antonio Agostino","family":"Sinisi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antonietta","family":"Rinaldi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michelangelo","family":"Faggiano","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2008,4,1]]},"container-title":["Neuroendocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/124519","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000124519","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T19:11:23Z","timestamp":1777662683000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000124519"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,1]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000124519","archive":["Portico"],"relation":{},"ISSN":["0028-3835","1423-0194"],"issn-type":[{"value":"0028-3835","type":"print"},{"value":"1423-0194","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,4,1]]}}}