A study of the association of the number of vascular-metabolic comorbidities with cognitive function and depression among community-dwelling older adults in Shanghai

OBJECTIVE: To investigate the associations of the number of vascular-metabolic comorbidities and individual diseases with mild cognitive impairment (MCI), cognitive function, and depression among community-dwelling older adults in Shanghai. METHODS: Using cross-sectional data from the Shanghai community sample of the Shanghai Aging Brain Health Cohort Study, 2 188 community-dwelling older adults aged ≥60 years were included, comprising 1 210 in the cognitively normal (CN) group and 978 in the MCI group. The number of vascular-metabolic comorbidities was calculated by summing 5 diseases: hypertension, diabetes, coronary heart disease, hyperlipidemia, and cerebral infarction. Binary Logistic regression and linear regression were used to analyze the relationships of the number of comorbidities and individual diseases with MCI, the total score on the Beijing version of the Montreal Cognitive Assessment (MoCA), and the total score on the Geriatric Depression Scale (GDS). Multivariable models were adjusted for age, sex, years of education, body mass index, smoking history, and drinking history. RESULTS: Compared with the CN group, the MCI group was older, had fewer years of education, higher GDS total scores, lower MoCA total scores, higher proportions of hypertension, coronary heart disease, and cerebral infarction, and a lower proportion of hyperlipidemia; the differences were statistically significant (P＜0.05). The number of vascular-metabolic comorbidities was associated with an increased risk of MCI and lower MoCA total scores in the unadjusted models, but these associations were not statistically significant after multivariable adjustment. The association between the number of vascular-metabolic comorbidities and higher GDS total scores persisted in the multivariable model (P＜0.01). Multivariable analyses of individual diseases showed that cerebral infarction was associated with an increased risk of MCI, lower MoCA total scores, and higher GDS total scores (all P＜0.01). After excluding patients with cerebral infarction, no statistically significant associations were observed between the number of vascular-metabolic comorbidities and the risk of MCI or MoCA total scores, but the association with higher GDS total scores persisted (P＜0.01). CONCLUSIONS: The associations between the number of vascular-metabolic comorbidities and cognitive outcomes among community-dwelling older adults in Shanghai weakened after multivariable adjustment. The relationships of cerebral infarction with MCI, MoCA total scores, and GDS total scores were relatively stable, and the association between the number of vascular-metabolic comorbidities and higher GDS total scores was relatively stable.