Evidence map›Paper›PMID 39956945›Full record

ArticleJournal of cachexia, sarcopenia and muscle2025

Aged-Related Fibroblast Activation Protein Expression in Skeletal Muscles Evaluated by PET Imaging.

Minseok Suh, Joonhyung Gil, Yeon-Koo Kang, Hongyoon Choi, Gi Jeong Cheon

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Article in Journal of cachexia, sarcopenia and muscle, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Minseok SuhDepartments of Nuclear Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Joonhyung GilDepartments of Nuclear Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Yeon-Koo KangDepartments of Nuclear Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Hongyoon ChoiDepartments of Nuclear Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.ORCID 0000-0002-8895-2449
Gi Jeong CheonDepartments of Nuclear Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundFibroblast activation protein (FAP) is prominently involved in the tumour microenvironment and tissue remodelling processes in most cancers, and its expression is also noted in normal skeletal muscle. This study aims to explore the relationship between FAP expression and age-related muscle characteristics through FAP inhibitor (FAPI) PET/CT imaging.

methodsThis retrospective analysis studied 54 patients with lung cancer (n = 27) and pancreatic cancer (n = 27) using FAPI PET/CT. Imaging-based muscle features including the mean standardised uptake value (SUVmean), skeletal muscle index (SMI) and Hounsfield units (HU) were evaluated. Age-related FAP expression in skeletal muscles was also evaluated using the Genotype-Tissue Expression (GTEx) dataset. Statistical analyses included Spearman's rank correlation and Kruskal-Wallis test, with a p-value of less than 0.05 considered significant.

resultsAnalysis revealed a moderate to strong positive correlation between FAPI SUVmean and age (ρ = 0.368, p = 0.006), with older age groups showing higher muscle uptake. Within specific cohorts, the FAPI-74 group demonstrated a stronger correlation (ρ = 0.500, p = 0.008) compared to the FAPI-46 group (ρ = 0.319, p = 0.105). SUVmean also correlated negatively with muscle density (HU) (ρ = -0.298, p = 0.029), suggesting an association with higher fat infiltration. GTEx data supported these findings, showing a significant increase in FAP expression across age groups (p < 0.001), with the highest median FAP in the 70-79 age group.

conclusionsThis study demonstrates an age-related increase in FAPI uptake in skeletal muscle, correlated with changes in muscle density and fat infiltration. The role of FAP extends beyond pathology to normal muscle, indicating broader biological functions. Accordingly, FAPI PET shows promise for assessing age-related muscle health and quality.

Indexed as

AgingGelatinasesMembrane ProteinsMuscle, SkeletalPositron Emission Tomography Computed TomographySerine EndopeptidasesAdultAgedAged, 80 and overEndopeptidasesFemaleFibroblast Activation Protein AlphaHumansMaleMiddle AgedPositron-Emission TomographyEndopeptidasesFibroblast Activation Protein AlphaGelatinasesMembrane ProteinsSerine EndopeptidasesageingFAPFAPI PETmuscle densityskeletal muscle

Identifiers

PMID39956945
PMCPMC11830633

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.