フレイル症候群に対する身体活動介入：ナラティブレビュー

Frailty is a geriatric syndrome characterised by a decline in functional reserves as the body ages, resulting in increased disability, comorbidity, and mortality. With trends towards ageing populations, frailty syndrome becomes more clinically relevant, highlighting the importance of appropriately preventing and managing the characteristics of frailty syndrome. Risk factor modification is recommended to delay or prevent the onset of frailty, including physical activity alongside other modifiable behaviours such as diet. Ageing is associated with chronic low-grade inflammation, resulting in reduced muscle protein synthesis and increased resistance to insulin, which both contribute to sarcopenia. Sarcopenia underpins key characteristics of frailty, including weakness and slow speed. Physical activity stimulates anabolic pathways and improves insulin resistance, reducing sarcopenia. Moreover, aerobic exercise is responsible for increasing the VO₂ peak, whilst resistance exercise improves muscle strength, both of which are known to decrease in frail elders. This narrative review primarily explored the effectiveness of physical activity in reducing the risk of the onset of frailty syndrome through a narrative review of the relevant literature concerning this subject. A secondary focus of this narrative review is to compare the success of alternative interventions for preventing frailty, relative to physical activity. Physical activity interventions have been shown to improve components of frailty scoring and selected biological markers of frailty, with evidence suggesting physical activity is an effective single-domain intervention for frailty; however, multidomain approaches may result in a greater overall improvement in frailty prevention. Further research is required to identify the types of exercise that modify specific aspects of Fried et al.'s frailty criteria (FFC), as well as what interventions can be used alongside physical activity, to holistically treat all characteristics of frailty syndrome.