Diabetes mellitus and risk of incident dementia in APOE ɛ4 carriers: an updated meta-analysis

Abstract

Background and aim Diabetes raises the risk of dementia, mortality, and cognitive decline in the elderly, potentially because of hereditary variables such as APOE. In this study, we aim to evaluate Diabetes mellitus and the risk of incident dementia in APOE ɛ4 carriers. Method We thoroughly searched PubMed (Medline), Scopus, and Google Scholar databases for related articles up to September 2023. The titles, abstracts, and full texts of articles were reviewed; data were extracted and analyzed. Result This meta-analysis included nine cohorts and seven cross-sectional articles with a total of 42,390 population. The study found that APOE ɛ4 carriers with type 2 diabetes (T2D) had a 48% higher risk of developing dementia compared to non-diabetic carriers (Hazard Ratio;1.48, 95%CI1.36–1.60). The frequency of dementia was 3 in 10 people (frequency: 0.3; 95%CI (0.15–0.48). No significant heterogeneity was observed. Egger’s test, which we performed, revealed no indication of publication bias among the included articles (p = 0.2). Conclusion Overall, diabetes increases the risk of dementia, but further large-scale studies are still required to support the results of current research.