Conversion of Mild Cognitive Impairment to Dementia among Subjects with Diabetes: A Population-Based Study of Incidence and Risk Factors with Five Years of Follow-up

Abstract

Type 2 diabetes mellitus (T2DM) is associated with dementia. Mild cognitive impairment (MCI) is a key determinant in this association. It is not clear whether T2DM increases the risk of conversion from MCI to dementia. We plan to explore the relationship between T2DM-MCI and dementia and identify its potential risk factors. A prospective community-based cohort study was conducted from March 2010 to March 2014, including 634 participants with T2DM-MCI, 261 T2DM participants who were cognitively intact, and 585 MCI participants without diabetes. All cohort members received detailed annual evaluations to detect dementia onset during the 5 years of follow-up. The three cohorts were compared to assess differences in dementia onset. Furthermore, Cox proportional hazards regression was used to identify risk factors for dementia onset in the T2DM-MCI cohort. During follow-up, 152 and 49 subjects developed dementia in the MCI and cognitively-intact cohorts, amounting to an adjusted hazard ratio (HR) of 1.66 (95% CI 1.07-2.26). In a survival analysis of the cohorts, MCI accelerated the median progression to dementia by 2.74 years. In a multivariable analysis of the T2DM-MCI cohort, major risk factors for dementia were age >75 years and longer durations of diabetes, while significantly reduced risks of dementia were associated with oral hypoglycemic agents and HMG-CoA reductase inhibitors. Insulin was not associated with significantly changed risk. T2DM-MCI may aggravate the clinical picture as a concomitant factor. To minimize progression to dementia, it may be worthwhile to target several modifiable diabetes-specific features, such as the duration of disease, glycemic control, and antidiabetic agents.

Humans with Type-2 Diabetes Show Abnormal Long-Term Potentiation-Like Cortical Plasticity Associated with Verbal Learning Deficits

“…While the sample size is consistent with recently-published work on diabetes and cognitive aging [7, 56, 57], it is relatively small when compared to large-scale epidemiological studies [58]. Further, we enrolled a relatively homogenous population of non-demented adults.…”

Neurocognitive Impairment as Systemic Effects of COPD

“…There is debate whether screening for cognitive impairment should be routinely applied. From the point of view of the hypoxemia approach, the answer to this debate will have to consider the evidence: (1) one in four people with COPD have cognitive impairment and over time, cognitive decline will deepen (risking an evolution toward multi-infarct dementia or Alzheimer disease) [92][93][94]. (2) It is now recognized that not only continuous, but also intermitent hypoxia (eforts, daily activities and sleep) can by repetition cause changes in brain neurochemistry and structure [7,36].…”

An Update on Type 2 Diabetes Mellitus as a Risk Factor for Dementia

“…High blood pressure [73] and older age [70] were risk factors for cognition impairments while education had a protective role against dementia [70]. Older age (>75 years) and long duration of diabetes are major risk factors for converting MCI to dementia, while the use of oral hypoglycemic agents or statins was associated with a significantly reduced risk for converting MCI to dementia [74]. T2DM has been found to be associated with MCI or MCI subtypes in middle-aged (50-65 years old) subjects but not in elderly individuals (66-80 years old) [72].…”