{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T16:25:39Z","timestamp":1790267139398,"version":"4.1.0"},"reference-count":0,"publisher":"Oxford University Press (OUP)","license":[{"start":{"date-parts":[[2025,8,12]],"date-time":"2025-08-12T00:00:00Z","timestamp":1754956800000},"content-version":"am","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Treatment of boys with delayed puberty (DP) with aromatase inhibitor or low-dose testosterone (T) induces different hormonal milieus allowing assessment of the relative roles of sex steroids in bone metabolism.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Design<\/jats:title>\n                  <jats:p>A prospective randomized controlled trial (NCT01797718).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Peripheral quantitative computed tomography (pQCT) of the non-dominant arm and left leg was performed in 27 boys with DP. Fifteen boys were treated with letrozole (Lz) (2.5 mg\/d) and twelve boys with T (1 mg\/kg every 4 weeks) for 6 months. pQCT scans were performed at 0, 6, and 12 months. Circulating bone status indices were measured at 0, 3, 6, and 12 months.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Between 0 and 3 months, levels of bone formation markers (P1NP, BAP) increased more in the T-group than in the Lz group (p=0.001-0.014). Accordingly, T-treated boys exhibited greater gain in bone mineral content (BMC) between 0 and 6 mo at distal site of tibia than the boys in the Lz-group (mean 18.1 mg\/mm [25.4] vs. -1.8 mg\/mm [SD 1.0], respectively, p=0.043). No significant between-group differences were observed in cortical or endosteal parameters. In both groups, the changes in testosterone levels during the treatment correlated positively with changes in BMC at distal radius (both p=0.041).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Testosterone treatment increased bone formation markers and predicted greater BMC accrual than letrozole at metabolically active skeletal sites. These findings reinforce the anabolic role of androgens, partly mediated by estrogens, in early pubertal bone development. A short, 6-month treatment with letrozole did not appear detrimental to bone accrual based on pQCT parameters. However, these findings do not allow conclusions regarding skeletal safety of longer Lz use.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1093\/ejendo\/lvaf160","type":"journal-article","created":{"date-parts":[[2025,8,8]],"date-time":"2025-08-08T12:09:55Z","timestamp":1754654995000},"source":"Crossref","is-referenced-by-count":1,"title":["Impact of Aromatase Inhibition on Bone Mineral Density and Structure: A Randomized Controlled Trial in Boys With Delayed Puberty"],"prefix":"10.1093","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6294-4563","authenticated-orcid":false,"given":"Tero","family":"Varimo","sequence":"first","affiliation":[{"name":"New Children\u2019s Hospital, Helsinki University Hospital, Pediatric Research Center , Helsinki ,","place":["Finland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P\u00e4ivi J","family":"Miettinen","sequence":"additional","affiliation":[{"name":"New Children\u2019s Hospital, Helsinki University Hospital, Pediatric Research Center , Helsinki ,","place":["Finland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hanna","family":"Huopio","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Kuopio University Hospital"},{"name":"Institute of Clinical Medicine, University of Eastern Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5948-1222","authenticated-orcid":false,"given":"Toni","family":"Rikkonen","sequence":"additional","affiliation":[{"name":"Musculoskeletal Research Unit, University of Eastern Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raimo","family":"Voutilainen","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Kuopio University Hospital"},{"name":"Institute of Clinical Medicine, University of Eastern Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sirpa","family":"Tenhola","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Kymenlaakso Central Hospital , Kotka ,","place":["Finland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5385-434X","authenticated-orcid":false,"given":"Taneli","family":"Raivio","sequence":"additional","affiliation":[{"name":"New Children\u2019s Hospital, Helsinki University Hospital, Pediatric Research Center , Helsinki ,","place":["Finland"]},{"name":"Stem Cells and Metabolism Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki , Helsinki ,","place":["Finland"]},{"name":"Department of Physiology, Faculty of Medicine, University of Helsinki"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matti","family":"Hero","sequence":"additional","affiliation":[{"name":"New Children\u2019s Hospital, Helsinki University Hospital, Pediatric Research Center , Helsinki ,","place":["Finland"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2025,8,12]]},"container-title":["European Journal of Endocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ejendo\/advance-article-pdf\/doi\/10.1093\/ejendo\/lvaf160\/64027597\/lvaf160.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ejendo\/advance-article-pdf\/doi\/10.1093\/ejendo\/lvaf160\/64027597\/lvaf160.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,13]],"date-time":"2025-08-13T00:57:31Z","timestamp":1755046651000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ejendo\/advance-article\/doi\/10.1093\/ejendo\/lvaf160\/8232542"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,12]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/ejendo\/lvaf160","relation":{},"ISSN":["0804-4643","1479-683X"],"issn-type":[{"value":"0804-4643","type":"print"},{"value":"1479-683X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,12]]},"article-number":"lvaf160"}}