Colaianni G, Errede M, Sanesi L, et al. - Skeletal muscle in both mice and humans produce a myokine named irisin during exercise. As per data in humans, irisin is positively linked with bone mineral density (BMD) in athletes and a population of healthy children. Researchers here examined the role of this myokine regarding the state of muscle and bone in the same population. They recruited 62 patients (age 68.71 ± 12.31 years) undergoing total hip or knee replacement for this purpose. They observed a negative correlation of irisin serum levels with age and their positive correlation with femoral BMD and vertebral BMD. Interestingly, lower irisin levels were identified in patients with osteopenia/osteoporosis (OP) compared with healthy controls, by analyzing patients divided by their T‐score. By analyzing the senescence marker p21, a significant rise in its mRNA expression was observed in the bone biopsies of OP patients compared with control ones. Overall, findings suggest correlation of higher irisin levels with a lower rate of age‐related osteoporosis and a possible effectiveness of irisin in delaying the osteoblast aging process, suggesting a potential senolytic action of this myokine.