Association of Cardiometabolic Multimorbidity with Dementia and Alzheimer’s Plasma Biomarkers in Older Adults: a population‐based study

Abstract

AbstractBackgroundIndividual cardiometabolic disorders are associated with an increased dementia risk. However, the relationship of cardiometabolic multimorbidity (CMM) with dementia has not been studied in Chinese older adults and the underlying mechanisms are poorly understood.MethodThis population‐based study included 5665 rural‐dwelling adults (age ≥60 years, 57.3% women) in the baseline examination (March‐September 2018) of the Multimodal Interventions to Delay Dementia and Disability in Rural China study. Cardiometabolic diseases (CMDs), which included heart disease, stroke, type 2 diabetes, and obesity, were assessed through clinical and neurological examinations. CMM was defined as the concurrent presence of two or more CMDs. Amyloid‐β(Aβ), total tau, and neurofilament light chain (NfL) were measured using Simoa platform in a subsample (n = 1434). Dementia, Alzheimer’s disease (AD), and vascular dementia (VaD) were clinically diagnosed following international criteria. Data were analyzed using the general linear and logistic regression and mediation models.ResultOf the 5665 participants, 1091 (19.26%) were detected with CMM, and 302 (5.33%) were diagnosed with dementia (193 with AD and 98 with VaD). The multivariable‐adjusted odds ratios of CMM (vs. no CMD) were 3.00 (95% confidence interval [CI] 2.19‐4.11) for all‐cause dementia, 1.66 (1.11‐2.47) for AD, and 12.5 (6.47‐24.18) for VaD. There was a significant interaction between CMM and sex on the likelihood of dementia and subtypes (P for interaction<0.05), such that the associations of CMM with dementia and subtypes were stronger in men than in women. In the biomarker subsample, CMM was significantly associated with higher plasma NfL (demographic‐adjusted β coefficient = 0.059; 95% CI 0.028‐0.091), Aβ40 (0.034; 0.018‐0.049), and Aβ42 (1.068; 0.636‐1.501); the observed association remained significant even in the multivariable‐adjusted model (P<0.001). The mediation analysis showed that plasma NfL could mediate 19.46% of the association between CMM and AD (P<0.05), whereas plasma Aβ and total tau showed no significant mediation (P>0.05).ConclusionCMM is associated with increased likelihoods of dementia, AD, and VaD in older adults, especially in men. Neurodegenerative pathway might play a part in the association of CMM with AD.