Author information

¹National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.

²NIHR Leicester Biomedical Research Centre, University Hospitals of Leicester NHS Trust and the University of Leicester, Leicester, UK.

³Clinical Nutrition Department, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.

⁴Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, UK.

⁵NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK.

⁶Lifespan and Population Health, School of Medicine, University of Nottingham, Nottingham, UK.

⁷Leicester Diabetes Centre, University Hospitals of Leicester NHS Trust, Leicester, UK.

⁸Diabetes Research Centre, University of Leicester, Leicester, UK.

⁹Laboratory of Metabolic Adaptations to Exercise Under Physiological and Pathological Conditions (AME2P), Université of Clermont Auvergne, Clermont-Ferrand, France.

¹⁰Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan.

¹¹Nottingham Digestive Diseases Centre, Translational Medical Sciences, School of Medicine, University of Nottingham, Nottingham, UK.

Abstract

Aims: To examine the impact of impaired glycaemic regulation (IGR) and exercise training on hepatic lipid composition in men with metabolic dysfunction-associated steatotic liver disease (MASLD).

Materials and methods: In Part A (cross-sectional design), 40 men with MASLD (liver proton density fat fraction [PDFF] ≥5.56%) were recruited to one of two groups: (1) normal glycaemic regulation (NGR) group (glycated haemoglobin [HbA1c] < 42 mmol·mol^-1 [<6.0%]; n = 14) or (2) IGR group (HbA1c ≥ 42 mmol·mol^-1 [≥6.0%]; n = 26). In Part B (randomized controlled trial design), participants in the IGR group were randomized to one of two 6-week interventions: (1) exercise training (EX; 70%-75% maximum heart rate; four sessions/week; n = 13) or (2) non-exercise control (CON; n = 13). Saturated (SI; primary outcome), unsaturated (UI) and polyunsaturated (PUI) hepatic lipid indices were determined using proton magnetic resonance spectroscopy. Additional secondary outcomes included liver PDFF, HbA1c, fasting plasma glucose (FPG), homeostatic model assessment of insulin resistance (HOMA-IR), peak oxygen uptake (VO₂ peak), and plasma cytokeratin-18 (CK18) M65, among others.

Results: In Part A, hepatic SI was higher and hepatic UI was lower in the IGR versus the NGR group (p = 0.038), and this hepatic lipid profile was associated with higher HbA1c levels, FPG levels, HOMA-IR and plasma CK18 M65 levels (r_s ≥0.320). In Part B, hepatic lipid composition and liver PDFF were unchanged after EX versus CON (p ≥ 0.257), while FPG was reduced and VO₂ peak was increased (p ≤ 0.030). ΔVO₂ peak was inversely associated with Δhepatic SI (r = -0.433) and positively associated with Δhepatic UI and Δhepatic PUI (r ≥ 0.433).

Conclusions: Impaired glycaemic regulation in MASLD is characterized by greater hepatic lipid saturation; however, this composition is not altered by 6 weeks of moderate-intensity exercise training.