| Popis: |
Midlife obesity and late-life weight loss confer a greater risk for developing dementia andAlzheimer’s disease (AD), but the exact mechanisms behind this phenomenon arecurrently unknown. The answer could lie on the involvement of gastrointestinal factors,such as adipokines (e.g., leptin, adiponectin, and resistin) and ghrelin. In this context, weconducted a pre-registered systematic review and meta-analysis of 38 cross-sectionaland 10 longitudinal studies targeting the associations between leptin, adiponectin,resistin, and ghrelin and the prevalence of general dementia, AD, and mild cognitiveimpairment (MCI). We also examined the relationship between the four gastrointestinalfactors and neurocognitive outcomes and AD-related cerebrospinal fluid biomarkers. ADpatients had lower blood leptin and higher resistin levels than cognitively normalparticipants. Lower leptin and higher resistin were associated with higher degree ofcognitive impairment. Additionally, lower late-life leptin levels might be associated withhigher prospective risk of dementia and AD, although more studies are needed tocorroborate this. Results in adiponectin and ghrelin were contradictory and notconclusive, with age, sex distribution, obesity, and severity of dementia seemingly actingas moderators across several analyses. Our work might contribute to the identificationof new preclinical blood markers of MCI and AD. |
