{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T12:01:49Z","timestamp":1790510509802,"version":"4.1.0"},"reference-count":3,"publisher":"S. Karger AG","issue":"5","license":[{"start":{"date-parts":[[2002,1,1]],"date-time":"2002-01-01T00:00:00Z","timestamp":1009843200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2002,1,1]],"date-time":"2002-01-01T00:00:00Z","timestamp":1009843200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gerontology"],"published-print":{"date-parts":[[2002]]},"abstract":"<jats:p>&lt;i&gt;Background:&lt;\/i&gt; Leptin, the product of the ob gene, is secreted by the adipocyte and is involved in the regulation of body weight, energy homeostasis and a wide spectrum of biological activities. &lt;i&gt;Objective:&lt;\/i&gt; We studied how variations in circadian serum leptin levels change as people age. &lt;i&gt;Methods:&lt;\/i&gt; Serum leptin levels were studied on a circadian basis in 26 men, 6 overweight (BMI &gt;27.8) and 20 with normal weight. The normal-weight men were divided into four age groups: (A)\u00a0in their 30s, (B)\u00a0in their 40s, (C)\u00a0in their 50s, and (D)\u00a0in their 60s. Serum samples were drawn at 2-hour intervals from 8:00 to 22:00 and hourly from 22:00 to 8:00 for a total of 24\u00a0h. &lt;i&gt;Results:&lt;\/i&gt; A significant circadian variation of leptin levels was found whatever the age with a peak at night and a trough around noon. The circadian leptin levels were higher in the older normal-weight groups (50s and 60s) and in the groups with a BMI &gt;27.8. &lt;i&gt;Conclusion:&lt;\/i&gt; Our study demonstrates that changes in the characteristics of the circadian rhythm of serum leptin in healthy men are associated with both advancing age and increased BMI.<\/jats:p>","DOI":"10.1159\/000065255","type":"journal-article","created":{"date-parts":[[2003,4,15]],"date-time":"2003-04-15T21:05:17Z","timestamp":1050440717000},"page":"309-314","source":"Crossref","is-referenced-by-count":11,"title":["Age-Related Modifications of Circadian Rhythm of Serum Leptin in Healthy Men"],"prefix":"10.1159","volume":"48","author":[{"given":"Zi-Yan","family":"Zhao","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yue-Rong","family":"Fu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin-Hua","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu-Yang","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andr\u00e9","family":"Bogdan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yvan","family":"Touitou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"127","published-online":{"date-parts":[[2002,8,16]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1038\/368425a0"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1016\/S0006-3223(97)00455-1"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1081\/CBI-100101052"}],"container-title":["Gerontology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/65255","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/65255","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,24]],"date-time":"2025-04-24T04:28:52Z","timestamp":1745468932000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000065255"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2002]]},"references-count":3,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2002,10,1]]}},"URL":"https:\/\/doi.org\/10.1159\/000065255","archive":["Portico"],"relation":{},"ISSN":["0304-324X","1423-0003"],"issn-type":[{"value":"0304-324X","type":"print"},{"value":"1423-0003","type":"electronic"}],"subject":[],"published":{"date-parts":[[2002]]}}}