Michael J Toth1, Damien M Callahan2, Mark S Miller3, Timothy W Tourville4, Sarah B Hackett2, Marion E Couch5, Kim Dittus2. 1. Department of Medicine, University of Vermont, College of Medicine, Burlington, VT, USA; Department of Molecular Physiology and Biophysics, University of Vermont, College of Medicine, Burlington, VT, USA; Department of Orthopaedics and Rehabilitation, University of Vermont, College of Medicine, Burlington, VT, USA. Electronic address: michael.toth@uvm.edu. 2. Department of Medicine, University of Vermont, College of Medicine, Burlington, VT, USA. 3. Department of Molecular Physiology and Biophysics, University of Vermont, College of Medicine, Burlington, VT, USA. 4. Department of Orthopaedics and Rehabilitation, University of Vermont, College of Medicine, Burlington, VT, USA. 5. Department of Surgery, University of Vermont, College of Medicine, Burlington, VT, USA.
Abstract
BACKGROUND & AIMS: Cancer patients frequently experience weight loss, with negative consequences for functionality and prognosis. The extent to which muscle atrophy contributes to weight loss, however, is not clear, as few studies have directly measured muscle fiber morphology in cancer patients. METHODS: Whole body and regional tissue composition were measured, along with the cross-sectional area (CSA) and fiber type of mechanically-isolated, single muscle fibers, in 19 cancer patients (8 with a history of weight loss, 11 weight-stable) and 15 non-diseased controls. RESULTS: Whole body fat mass was reduced in cancer patients with a history of weight loss, but no differences in whole body or leg fat-free mass were apparent. In contrast, reductions (∼20%) in single muscle fiber CSA were found in both slow-twitch, myosin heavy chain (MHC) I and fast-twitch, MHC IIA fibers in both weight-stable patients and those with a history of weight loss. Fiber type distribution showed a shift towards a fast-twitch phenotype compared to controls, which may preserve muscle function in cancer patients despite atrophy, as positive relationships were found between the fractions of hybrid MHC IIAX and I/IIA fibers and 6-min walk performance. CONCLUSIONS: Our results suggest that, although not apparent from whole body or regional measurements, cancer is associated with reduced skeletal muscle fiber size independent of weight loss history and a shift towards fast-twitch fibers, phenotypes that resemble adaptations to muscle disuse.
BACKGROUND & AIMS:Cancerpatients frequently experience weight loss, with negative consequences for functionality and prognosis. The extent to which muscle atrophy contributes to weight loss, however, is not clear, as few studies have directly measured muscle fiber morphology in cancerpatients. METHODS: Whole body and regional tissue composition were measured, along with the cross-sectional area (CSA) and fiber type of mechanically-isolated, single muscle fibers, in 19 cancerpatients (8 with a history of weight loss, 11 weight-stable) and 15 non-diseased controls. RESULTS: Whole body fat mass was reduced in cancerpatients with a history of weight loss, but no differences in whole body or leg fat-free mass were apparent. In contrast, reductions (∼20%) in single muscle fiber CSA were found in both slow-twitch, myosin heavy chain (MHC) I and fast-twitch, MHC IIA fibers in both weight-stable patients and those with a history of weight loss. Fiber type distribution showed a shift towards a fast-twitch phenotype compared to controls, which may preserve muscle function in cancerpatients despite atrophy, as positive relationships were found between the fractions of hybrid MHC IIAX and I/IIA fibers and 6-min walk performance. CONCLUSIONS: Our results suggest that, although not apparent from whole body or regional measurements, cancer is associated with reduced skeletal muscle fiber size independent of weight loss history and a shift towards fast-twitch fibers, phenotypes that resemble adaptations to muscle disuse.
Authors: Sophia Kapchinsky; Madhusudanarao Vuda; Kayla Miguez; Daren Elkrief; Angela R de Souza; Carolyn J Baglole; Sudhakar Aare; Norah J MacMillan; Jacinthe Baril; Paul Rozakis; Vita Sonjak; Charlotte Pion; Mylène Aubertin-Leheudre; Jose A Morais; R Thomas Jagoe; Jean Bourbeau; Tanja Taivassalo; Russell T Hepple Journal: J Physiol Date: 2018-05-19 Impact factor: 5.182
Authors: Michael J Toth; Thomas B Voigt; Timothy W Tourville; Shannon M Prior; Blas A Guigni; Axel V Schlosberg; Isaac B Smith; Taylor J Forest; Peter A Kaufman; Marie E Wood; Hibba Rehman; Kim Dittus Journal: J Appl Physiol (1985) Date: 2020-05-07
Authors: Kevin A Murach; Cory M Dungan; Kate Kosmac; Thomas B Voigt; Timothy W Tourville; Mark S Miller; Marcas M Bamman; Charlotte A Peterson; Michael J Toth Journal: J Appl Physiol (1985) Date: 2019-11-07
Authors: Peter Soldos; Zsuzsanna Besenyi; Katalin Hideghéty; László Pávics; Ádám Hegedűs; Levente Rácz; Bence Kopper Journal: Pathol Oncol Res Date: 2021-06-29 Impact factor: 3.201