Prof Gianni Biolo
Department of Medical Sciences
University of Trieste
Trieste, Italy

A Multimodal Intervention to Prevent Muscle Atrophy, Insulin Resistance and Functional Decline During  Experimental Bed Rest in Elderly Individuals

Filippo Giorgio Di Girolamo¹, Kaja Teraž^1,2, Bostjan Simunic², Luka Šlosar², Uros Marusic², Saša Pišot², Maira Camargo³, Alja Ivetac¹, Bruno Grassi⁴, Nicola Fiotti¹, Martino Franchi³, Marco Narici³, Rado Pišot², and Gianni Biolo¹

¹Department of Medical Sciences, University of Trieste, Italy
²Science and Research Centre of Koper. Koper, Slovenia
³Department of Biomedical Sciences, University of Padua, Italy
⁴Department of Medicine, University of Udine¸ Italy

Short-term bed rest (BR) is a common practice for elderly patients hospitalized for acute medical or surgical conditions. In this study, we implemented a multimodal approach comprising complementary interventions designed to counteract the adverse BR effects on skeletal muscle, metabolic regulation, cognition, and physical performance. Twenty healthy elderly volunteers (68±3 yrs) were randomized into an intervention (INT) group and a control (CONT) group. Participants were assessed before and at the conclusion of 10 days of BR. The INT group underwent 30 days of exercise prehabilitation prior to BR and followed a leucine-rich, high-protein diet (1.6 g/kg/day) combined with daily virtual reality (VR) brain training during BR. Prehabilitation increased leg lean mass by 3.0±3.3%. During BR, quadriceps muscle volume significantly decreased. Muscle loss was three times lower in the INT group compared to the CONT group. Isometric maximal voluntary contraction of knee extensor muscles decreased in CONT but showed no significant change in INT. The decline in insulin sensitivity, measured by the Matsuda index, was more than twice as high in the CONT group compared to the INT group. The kinesthetic imagery score from the Movement Imagery Questionnaire improved in the INT group but not in CONT, and the time to complete the Foot Up and Go Test significantly improved in INT compared to CONT. In conclusion, we have developed an effective multimodal approach that mitigates inactivity-induced muscle atrophy, strength loss, insulin resistance, and declines in both physical and cognitive performance in aging individuals during short-term bed rest. This approach holds promise for clinical applications in hospitalized elderly populations.

This work has received funding from the X-BRAIN.net project of the Interreg VI-A Italy-Slovenia 2021-2027 and from project ASI Dry Immersion 2024-2026 N.2023-14.U.O (CUP) J93C23000670001 2024–2027.