IGF-1 and Muscle Health

Most muscle pathologies are characterized by the progressive loss of muscle tissue due to a chronic illness combined with the inability to regenerate the damaged muscle. These pathological changes, known as muscle wasting, can be attributed to alteration in muscle growth factors, specifically IGF-1. The administration of IGF-1 has been considered as a promising therapeutic intervention for advanced muscle weakness and wasting because of IGF-1’s role in skeletal muscle growth, survival, and regeneration. [211] Muscle wasting results primarily from accelerated protein degradation and is associated with increased synthesis of two muscle-specific ubiquitin ligases (a type of protein) known as atrogin-1 and muscle ring finger 1 (MuRF1). [212] Sacheck et al. reported that IGF-1 administration can prevent muscle wasting by stimulating muscle growth through suppression of protein breakdown and atrophy-related ubiquitin ligases, atrogin-1 and MuRF1. [213] Similarly, Nystom et al. found that IGF-1 attenuates sepsis-induced muscle wasting apparently by increasing muscle protein synthesis and potentially decreasing protein breakdown. [214] Numerous high quality studies assessing the therapeutic benefits of IGF-1 in patients with muscle wasting have also proved that the treatment may stimulate muscle repair, increase muscle mass, and improve muscle strength. [215-226]