{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T14:29:55Z","timestamp":1774621795424,"version":"3.50.1"},"reference-count":7,"publisher":"The Endocrine Society","issue":"3","license":[{"start":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T00:00:00Z","timestamp":1773360000000},"content-version":"vor","delay-in-days":18,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,2,23]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Klinefelter syndrome (KS) is the most prevalent sex chromosome disorder in men but often remains clinically silent until later life. We describe an elderly man whose evaluation for a rib fracture uncovered the diagnosis. A 76-year-old male presented after a low-impact fracture during a coughing episode. Clinical history revealed delayed sexual maturation, small testes, infertility, and mild gynecomastia. Hormonal testing demonstrated markedly reduced testosterone with elevated luteinizing and follicle-stimulating hormones, suggesting primary testicular failure. Karyotype analysis confirmed 47,XXY. Bone mineral density testing revealed osteopenia, meeting criteria for clinical osteoporosis. He received intravenous zoledronic acid, while androgen therapy was postponed pending urologic assessment. This case emphasizes that KS can remain undetected for decades and highlights the need to consider hypogonadism in men with unexplained bone loss. Early recognition facilitates appropriate treatment and long-term monitoring for associated systemic complications.<\/jats:p>","DOI":"10.1210\/jcemcr\/luag035","type":"journal-article","created":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T12:43:40Z","timestamp":1769863420000},"source":"Crossref","is-referenced-by-count":0,"title":["A case of osteoporotic fracture leading to diagnosis of Klinefelter syndrome in a 76-year-old man"],"prefix":"10.1210","volume":"4","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-1866-0441","authenticated-orcid":false,"given":"Joshua Nathan","family":"Shapiro","sequence":"first","affiliation":[{"name":"Division of Endocrinology, Diabetes & Metabolism, State University of New York, Downstate Medical Center , Brooklyn, NY 11203 ,","place":["USA"]},{"name":"Division of Endocrinology, Diabetes & Metabolism, Veterans Affairs New York Harbor Healthcare System , Brooklyn, NY 11209 ,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mihaela","family":"Oprea","sequence":"additional","affiliation":[{"name":"Division of Endocrinology, Diabetes & Metabolism, Veterans Affairs New York Harbor Healthcare System , Brooklyn, NY 11209 ,","place":["USA"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"80","published-online":{"date-parts":[[2026,3,13]]},"reference":[{"issue":"9430","key":"2026032709371380000_luag035-B1","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/S0140-6736(04)16678-6","article-title":"Klinefelter's syndrome","volume":"364","author":"Lanfranco","year":"2004","journal-title":"Lancet"},{"issue":"1","key":"2026032709371380000_luag035-B2","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1210\/jc.2012-2382","article-title":"Clinical review: Klinefelter syndrome\u2013a clinical update","volume":"98","author":"Groth","year":"2013","journal-title":"J Clin Endocrinol Metab"},{"issue":"5","key":"2026032709371380000_luag035-B3","doi-asserted-by":"crossref","first-page":"1715","DOI":"10.1210\/jc.2018-00229","article-title":"Testosterone therapy in men with hypogonadism: an endocrine society clinical practice guideline","volume":"103","author":"Bhasin","year":"2018","journal-title":"J Clin Endocrinol Metab"},{"key":"2026032709371380000_luag035-B4","author":"Centers for Disease Control and Prevention (CDC), National Center for Health Statistics"},{"issue":"8","key":"2026032709371380000_luag035-B5","doi-asserted-by":"crossref","first-page":"e230058","DOI":"10.1530\/EC-23-0058","article-title":"Osteoporosis and bone metabolism in patients with Klinefelter syndrome","volume":"12","author":"Grande","year":"2023","journal-title":"Endocr Connect"},{"issue":"6","key":"2026032709371380000_luag035-B6","doi-asserted-by":"crossref","first-page":"1802","DOI":"10.1210\/jc.2011-3045","article-title":"Osteoporosis in men: an endocrine society clinical practice guideline","volume":"97","author":"Watts","year":"2012","journal-title":"J Clin Endocrinol Metab"},{"issue":"1","key":"2026032709371380000_luag035-B7","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1111\/andr.12909","article-title":"European academy of andrology guidelines on Klinefelter syndrome endorsing organization: European Society of Endocrinology","volume":"9","author":"Zitzmann","year":"2021","journal-title":"Andrology"}],"container-title":["JCEM Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jcemcr\/article-pdf\/4\/3\/luag035\/67339507\/luag035.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jcemcr\/article-pdf\/4\/3\/luag035\/67339507\/luag035.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T13:37:17Z","timestamp":1774618637000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jcemcr\/article\/doi\/10.1210\/jcemcr\/luag035\/8519269"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,23]]},"references-count":7,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026,2,23]]}},"URL":"https:\/\/doi.org\/10.1210\/jcemcr\/luag035","relation":{},"ISSN":["2755-1520"],"issn-type":[{"value":"2755-1520","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,3]]},"published":{"date-parts":[[2026,2,23]]},"article-number":"luag035"}}