{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T05:02:49Z","timestamp":1790226169144,"version":"4.1.0"},"reference-count":17,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T00:00:00Z","timestamp":1790208000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012151","name":"Sanming Project of Medicine in Shenzen Municipality","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100012151","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>In boys aged \u226510 years with advanced bone age and impaired growth potential (baseline height SDS &amp;lt; \u22121.5, BA-CA \u22651.5 years, and PAH &amp;lt; \u22122 SDS), growth hormone monotherapy, while promoting linear growth, fails to delay skeletal maturation, thus limiting therapeutic efficacy. Although letrozole combined with growth hormone may theoretically \u201cdecouple\u201d height gain from epiphyseal closure, high-quality evidence specific to the advanced bone age population remains insufficient, and concerns regarding baseline bias and lack of long-term safety data persist. This study, based on real-world data, aims to clarify the benefits and risks of this combination regimen in promoting linear growth, delaying bone age progression, and improving adult height outcomes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A retrospective analysis was conducted on clinical data from 64 boys aged \u226510 years with advanced bone age and impaired growth potential treated in our hospital from June 2020 to December 2025 (baseline height SDS &amp;lt; \u22121.5, BA-CA \u22651.5 years, and PAH &amp;lt; \u22122 SDS). Patients were divided into a combination therapy group (letrozole + rhGH, n = 36) and a monotherapy group (rhGH alone, n = 28) according to treatment regimen. Changes in height, bone age, annual growth velocity, the ratio of bone age advancement to chronological age progression (\u0394BA\/\u0394CA), and sex hormone levels were compared between the two groups before and after treatment.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The mean annual growth velocity in the combination group was (7.7 \u00b1 1.2) cm\/year, significantly higher than that in the monotherapy group [(6.7 \u00b1 1.4) cm\/year,\n                      <jats:italic>P<\/jats:italic>\n                      &amp;lt; 0.05]. The \u0394BA\/\u0394CA ratio in the combination group was 0.85, significantly lower than that in the monotherapy group (1.12,\n                      <jats:italic>P<\/jats:italic>\n                      &amp;lt; 0.001), indicating better control of bone age progression. Among the 33 patients who had completed treatment, the mean final height was (171.2 \u00b1 3.5) cm in the combination group, compared to (169.8 \u00b1 4.1) cm in the monotherapy group (the difference was not statistically significant, P = 0.291).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>In boys aged \u226510 years with advanced bone age and impaired growth potential, letrozole combined with rhGH significantly improved annual growth velocity and delayed bone age progression compared with rhGH monotherapy. However, the difference in final adult height among those who completed treatment was not statistically significant (1.4 cm, P = 0.291). The significantly better control of bone age advancement (\u0394BA\/\u0394CA) and higher target-height attainment rate suggest a potential benefit of adding letrozole, but larger studies with more participants reaching final height are needed to confirm a meaningful effect on adult height.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fendo.2026.1940392","type":"journal-article","created":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T04:38:54Z","timestamp":1790224734000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Efficacy of letrozole combined with recombinant human growth hormone in boys aged \u226510 years with advanced bone age and impaired growth potential: a retrospective cohort study"],"prefix":"10.3389","volume":"17","author":[{"given":"Peipei","family":"Liu","sequence":"first","affiliation":[{"name":"Shenzhen Maternity and Child Healthcare Hospital, Women and Children\u2019s Medical 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China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wujin","family":"Wang","sequence":"additional","affiliation":[{"name":"Shenzhen Maternity and Child Healthcare Hospital, Women and Children\u2019s Medical Center, Southern Medical University","place":["Shenzhen, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guoqing","family":"Dong","sequence":"additional","affiliation":[{"name":"Shenzhen Maternity and Child Healthcare Hospital, Women and Children\u2019s Medical Center, Southern Medical University","place":["Shenzhen, Guangdong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,24]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1007\/s12098-023-04554-4","article-title":"Precocious puberty","volume":"90","author":"Banerjee","year":"2023","journal-title":"Indian J 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