BackgroundAdipokines secreted from adipose tissue may contribute to dementia pathogenesis.Objective: Our study investigated the associations between plasma levels of leptin, resistin, TNF-α, and IL-6 and the risk of all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD).MethodsPlasma protein levels were measured using the Olink Proximity Extension Assay, and dementia was ascertained from hospital admissions and death registries in the UK Biobank. Multivariable Cox proportional hazards models with stepwise covariate adjustments were used to assess associations. Subgroup analyses were conducted to examine whether the associations differed by sociodemographic characteristics, lifestyle factors, and major diseases.ResultsAmong 32,002 participants, 793 developed all-cause dementia, including 260 with AD and 96 with VaD. Plasma levels of resistin and IL-6 were positively associated with risks of all-cause dementia, with hazard ratios (95% confidence intervals) of 1.10 (1.03, 1.18) and 1.10 (1.04, 1.17), respectively. Leptin (0.98; 0.86, 1.12) and TNF-α levels (1.06; 0.98, 1.13) were not significantly associated with all-cause dementia. Resistin (1.28; 1.08, 1.53) and TNF-α levels (1.21; 1.04, 1.40) were associated with VaD risk. There was a lack of evidence for the associations between four adipokines and AD. Subgroup analyses showed stronger associations between resistin and all-cause dementia in those with high body mass index, diabetes, or stroke.ConclusionsPlasma levels of resistin and IL-6 were positively associated with risks of all-cause dementia, with resistin and TNF-α strongly linked to VaD. These findings support a potential role of adipokines in dementia pathogenesis, particularly for VaD.