Risk factors for dementia with type 2 diabetes mellitus among elderly people in China

Objective: to investigate the prevalence and risk factors of diabetes to dementia and its subtypes such as Alzheimer disease (AD) and vascular dementia (VD) among the Chinese elderly population. Methods: among 8,213 Chinese people aged 65 years and older, 1,109 subjects with type 2 diabetes millitus (T2DM) were ascertained by interview and direct glucose testing. All diabetic subjects were initially screened with the “DSM-IV criteria” for dementia and its subtypes. We compared the prevalence of dementia in diabetic patients with that in ordinary subjects, and analyzed the association of the status of diabetes with dementia including AD and VD. Logistic regression was used to assess OR of dementia and its subtypes with T2DM. Results: after a comprehensive geriatric and cognitive assessment, 132 diabetic subjects were diagnosed with all-cause dementia. The prevalence rate for dementia with T2DM was 1.61%. Of demented subjects, 37 subjects had AD, 30 subjects had VD. The prevalence rates for AD with T2DM and VD with T2DM were 4.51% and 3.65%, respectively. In the univariate analyses, among all diabetic subjects, compared with cognitive intactly subjects, the demented subjects, including AD and VD subjects, were older, more female had higher percentage of current smoking, had a greater duration of diabetes, took more frequent use of diabetes medications, and stronger effect of APOE e4 status. In multivariate logistic regression analyses, variables including age, APOE e4 allele, duration from onset of diabetes, using oral hypoglycemic agents, HMGCoA reductase (statins) were significantly associated with increased risk for dementia with T2DM (all P< 0.05). Conclusions: the present study shows that T2DM is associated with dementia and its subtypes amongst elderly people in the Chinese population.