{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T19:58:35Z","timestamp":1787169515133,"version":"build-2736575974"},"reference-count":31,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,4,25]],"date-time":"2025-04-25T00:00:00Z","timestamp":1745539200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Physiol."],"abstract":"\n Background<\/jats:title>\n Computed tomography (CT) imaging is a useful tool for assessing skeletal muscle mass and quality. The present study aimed to determine age- and sex-specific reference values for CT-based skeletal muscle markers in a healthy population, and to correlate them with serum creatinine and 24-h urinary creatinine excretion (24h-UCE).<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n Skeletal muscle index (SMI) - a marker of muscle mass\/quantity - and skeletal muscle radiation attenuation (SMRA) and intermuscular adipose tissue index (IMATI) - markers of muscle quality\/myosteatosis - were determined using a deep-learning-based method from axial CT images at the level of the 3\n rd<\/jats:sup>\n lumbar vertebra in living kidney donors assessed between 01\/2005 and 05\/2023. Age- and sex-specific reference values were determined by the 5\n th<\/jats:sup>\n percentile, and correlation was tested with the Pearson correlation coefficient.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n CT scans of 394 healthy individuals were included. The mean age was 53 years (SD 12), mean BMI was 25.2 kg\/m\n 2<\/jats:sup>\n (SD 3.9), and 130 patients (33%) were male. The reference values for low skeletal muscle mass (SMI) in males were 43.7 cm\n 2<\/jats:sup>\n \/m\n 2<\/jats:sup>\n (20\u201339 years), 44.9 cm\n 2<\/jats:sup>\n \/m\n 2<\/jats:sup>\n (40\u201359 years), and 39.7 cm\n 2<\/jats:sup>\n \/m\n 2<\/jats:sup>\n (\u226560 years). In females, the corresponding values were 33.8 cm\n 2<\/jats:sup>\n \/m\n 2<\/jats:sup>\n (20\u201339 years), 34.8 cm\n 2<\/jats:sup>\n \/m\n 2<\/jats:sup>\n (40\u201359 years), and 31.2 cm\n 2<\/jats:sup>\n \/m\n 2<\/jats:sup>\n (\u226560 years). SMI showed a moderate correlation with serum creatinine (r = 0.452, p &lt; 0.001) but a weak correlation with 24h-UCE (r = 0.188, p = 0.003). Correlations were all weak for SMRA (creatinine: r = 0.220, p &lt; 0.001; 24h-UCE: r = 0.177, p = 0.006) and IMATI (creatinine: r = \u22120.101, p = 0.054; 24h-UCE, r = \u22120.108, p = 0.093).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n The age- and sex-specific reference values reported here could be used in clinical practice and future studies to identify patients at risk of muscle decline.<\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fphys.2025.1566463","type":"journal-article","created":{"date-parts":[[2025,4,25]],"date-time":"2025-04-25T01:22:48Z","timestamp":1745544168000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Age- and sex-specific reference values for CT-based low skeletal muscle quantity and quality in healthy living kidney donors"],"prefix":"10.3389","volume":"16","author":[{"given":"David","family":"Martin","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paola","family":"Dolce","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martin","family":"H\u00fcbner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tobias","family":"Zingg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Fuks","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Pierre","family":"Venetz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Damien","family":"Maier","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maurice","family":"Matter","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabio","family":"Becce","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,4,25]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"436","DOI":"10.1136\/bjsm.37.5.436","article-title":"Sex differences in whole body skeletal muscle mass measured by magnetic resonance imaging and its distribution in young Japanese adults","volume":"37","author":"Abe","year":"2003","journal-title":"Br. 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