Abstract

Background: Physical frailty is an age-related clinical condition associated with deterioration of physiological capacity. In aged mice, increased RNA expression of metabolism-related genes in circulating white blood cells (WBC) correlates with impaired physical function.

Methods: Twenty elderly volunteers were enrolled in this exploratory analysis and the possible link between RNA expression of metabolism-related genes in WBC and impairment of their physical function was investigated (jRCT1050210166. Feb. 02, 2022). In mechanism of action studies, cellular interactions between WBC and cells in muscle tissue were investigated in mice.

Results: RNA expression of metabolism-related genes, such as glucose transporter 1 (Glut1), Glut3, AMP-activated protein kinase A, and prolyl hydroxylase 3, was significantly increased in aged individuals with swallowing dysfunction and masticatory disturbance compared to those without these symptoms. The level of metabolism-related RNA expression significantly decreased with walking habits compared to no walking habits. Studies in mice have revealed a direct link between circulating WBC and endothelium/satellite cells via gap junction.

Conclusions: Our results indicate that the level of metabolism-related RNA expression in WBC can serve as a marker of impaired physical function in the elderly and that circulating WBC may have a previously unknown physiological role in maintaining physical function.