Risk Factors Associated with Transition to Dementia in Patients with Mild Cognitive Impairment

Objectives: This study assessed the effects of risk factors on the transition from mild cognitive impairment (MCI) to dementia using a cohort of patients with MCI. Methods: The data collected for the Alzheimer’s Disease Neuroimaging Initiative (ADNI) study include the cognitive assessments and clinical information of patients who were diagnosed with MCI at study entry. The distribution of the time from MCI to dementia and its association with patient genetic and demographic factors were estimated by using a parametric approach for left-truncated data with the uncertain disease onset. We considered the number of apolipoprotein E4 (ApoE4) alleles, age, sex, and education level as the risk factors. Results: Aging and the presence of at least one ApoE4 allele increased the risk for transition from MCI to dementia. The distribution of the time from MCI to dementia did not vary with sex and education level. Conclusions: It is necessary to develop strategies for early detection of MCI in carriers of the ApoE4 allele because they are more likely to develop dementia in a relatively short time, compared to non-carriers of the ApoE4 allele.