Physical activity and immunity in obese older adults: A systematic bibliographic analysis

Extensive research has been conducted on the roles of physical activity in immune functioning. However, reviews on the effect of physical activity on immune function among obese older adults are scarce. This study aimed to map the trend and development of the key terms and prominent sources to identify potential research opportunities through a systematic bibliographic analysis. A systematic search was conducted in the Scopus database on the following query: (sport∗ OR "physical activity" OR exercise) AND (elderly OR "older adult∗" OR aging) AND (immun∗) AND (obes∗) AND NOT (animal), in March 2023. Publication timing and citation were descriptively analyzed, followed by the bibliographic coupling and the term co-occurrence analyses for generating network and overlay visualization mapping using the VOSviewers software. The search resulted in 426 articles dating back from 1991 to the present and were dominated by authors from Western countries. Three thematic clusters of this research area were generated, covering (1) the impact of physical activity or inactivity on health, (2) physical activity assessments and the use of association and cross-sectional study as the primary type of research, and (3) the physical activity impacts at the population level. For future research, more intervention studies are needed to understand how exercise affects immune response in older obese adults and to explore optimal duration, type, and intensity of the exercise, using a multi-omics approach. Studies in non-Western populations and systematic reviews are recommended to complement this bibliographic analysis.