Modifiable risk factors for mild cognitive impairment among cognitively normal community-dwelling older adults: A systematic review and meta-analysis

Although numerous studies have investigated modifiable risk factors for mild cognitive impairment (MCI) among community-dwelling seniors, no meta-analysis has summarized these findings. Five databases were searched from January 1, 2000, to December 30, 2023. The protocol was registered with PROSPERO. Data were extracted and reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant meta-analyses of modifiable risk factors were performed. The evidence of each factor was assessed by the GRADE for cohort studies. Of 16,651 citations, 87 studies involving 225,584 community-dwelling seniors were included. Fourteen meta-analyses involving 20 studies with 44,199 participants were performed. The analyses revealed low-to-moderate-quality evidence supporting that diabetes, 2 or more comorbidities, anxiety, apathy, depressive symptoms, and physical frailty were risk factors for incident MCI in older adults. Conversely, hypertension, agitation, and irritability might not be risk factors. Additionally, moderate-quality evidence supports the protective effect of engaging in cognitive-demanding activities on the onset of MCI. Collectively, this study constitutes the first extensive compilation of evidence regarding the various risk factors for the development of MCI in older adults. Our findings hold significant potential to guide the formulation of prevention and management strategies to either prevent or potentially reverse the onset of MCI.