Serum transthyretin and aminotransferases are associated with lean mass in people with coronary heart disease: Further insights from the CARE-CR study

Emily James; Stuart Goodall; Simon Nichols; Karen Walker; Sean Carroll; Alasdair F O'Doherty; Lee Ingle

doi:10.3389/fmed.2023.1094733

Serum transthyretin and aminotransferases are associated with lean mass in people with coronary heart disease: Further insights from the CARE-CR study

Front Med (Lausanne). 2023 Feb 20:10:1094733. doi: 10.3389/fmed.2023.1094733. eCollection 2023.

Authors

Emily James^{1

2

3}, Stuart Goodall¹, Simon Nichols^{4

5}, Karen Walker⁶, Sean Carroll⁷, Alasdair F O'Doherty¹, Lee Ingle⁷

Affiliations

¹ Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom.
² Diabetes Research Centre, University of Leicester, Leicester, United Kingdom.
³ NIHR Leicester Biomedical Research Centre, Leicester, United Kingdom.
⁴ Sport and Physical Activity Research Group, Sheffield Hallam University, Sheffield, United Kingdom.
⁵ Advanced Wellbeing Research Centre, Sheffield Hallam University, Sheffield, United Kingdom.
⁶ Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
⁷ School of Sport, Exercise and Rehabilitation Sciences, University of Hull, Hull, United Kingdom.

Abstract

Background: Low muscle mass disproportionately affects people with coronary heart disease compared to healthy controls but is under-researched and insufficiently treated. Inflammation, poor nutrition, and neural decline might contribute to low muscle mass. This study aimed to assess circulatory biomarkers related to these mechanisms [albumin, transthyretin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and C-terminal agrin fragment] and their relationship with muscle mass in people with coronary heart disease. Our findings could be beneficial to indicate mechanisms of sarcopenia, detect sarcopenia, and evaluate treatment.

Methods: Serum blood samples from people with coronary heart disease were analysed for biomarker concentrations using enzyme-linked immunosorbent assays. Skeletal muscle mass was estimated using dual X-ray absorptiometry derived appendicular lean mass and reported as skeletal muscle index (SMI; kg m^-2), and as a proportion of total body mass [appendicular skeletal mass (ASM%)]. Low muscle mass was defined as a SMI <7.0 and <6.0 kg m^-2, or ASM% <25.72 and <19.43% for men and women, respectively. Associations between biomarkers and lean mass were adjusted for age and inflammation.

Results: Sixty-four people were assessed; 14 (21.9%) had low muscle mass. People with low muscle mass had lower transthyretin (effect size 0.34, p = 0.007), ALT (effect size 0.34, p = 0.008), and AST (effect size 0.26, p = 0.037) concentrations, compared to those with normal muscle mass. SMI was associated with inflammation-corrected ALT (r = 0.261, p = 0.039) and with inflammation- and age-adjusted AST/ALT ratio (r = -0.257, p = 0.044). Albumin and C-terminal agrin fragment were not associated with muscle mass indices.

Conclusion: Circulatory transthyretin, ALT and AST were associated with low muscle mass in people with coronary heart disease. Low concentrations of these biomarkers might indicate that low muscle mass is partially explained by poor nutrition and high inflammation in this cohort. Targeted treatments to address these factors could be considered for people with coronary heart disease.

Keywords: agrin; albumin; aminotransferases; biomarkers; coronary heart disease; muscle; sarcopenia; transthyretin.