Effects of regular exercise on inflammasome activation-related inflammatory cytokine levels in older adults: a systematic review and meta-analysis.

Exercise has been found to play important roles in regulating inflammation, although the mechanisms are unclear. The present systematic review and meta-analysis aimed to investigate whether regular exercise could regulate inflammation through inflammasome activation signalling in older adults. Five databases were searched, and 19 randomised controlled trials (RCTs) studying effects of regular exercise on inflammasome activation-related inflammatory cytokines interleukin (IL)-1β and IL-18 and other key molecules involved in inflammasome activation signalling such as NOD-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1 in older adults aged 50 years or older were included. The results showed that regular exercise could significantly decrease the levels of IL-1β and IL-18, important end-products of inflammasome activation in older adults. Subgroup analyses showed that aerobic exercise is the most effective training modality, and low-to-moderate intensity and mixed intensity are better compared with high intensity to decrease IL-1β and IL-18. The effect of regular exercise on key molecules involved in inflammasome activation signalling including NLRP3, ASC and caspase-1 is understudied and needs to be further investigated. These findings demonstrate that regular exercise could effectively decrease inflammasome activation-related inflammatory cytokine levels in older adults.