Progression from normal cognition to mild cognitive impairment in a diverse clinic‐based and community‐based elderly cohort

Abstract

Importance Investigation of the conversion rates from normal cognition (NC) to mild cognitive impairment (MCI) is important, as effective early intervention could potentially prevent or substantially delay the onset of dementia. However, reported conversion rates differ across studies and recruitment source. Objective Our study examined predictors of conversion from NC to MCI in a racially and ethnically diverse sample drawn both from community and clinic recruitment sources. Design Rates and predictors of conversion were assessed in an ongoing prospective longitudinal study at University of California, Davis, Alzheimer’s Disease Center from 2000 to 2015. Setting Participants were recruited through a clinic (5%) and community sample (95%). Participants Participants (n = 254) were clinically confirmed as cognitively normal at baseline and followed up to seven years. Exposures Recruitment source, demographic factors (age, gender, race/ethnicity, year of education, APOE ε4 positive), cognitive measures (SENAS test scores), functional assessments (CDR sum of boxes), and neuroimaging measures (total brain volume, total hippocampal volume, white hyperintensity volume). Main outcome measure Conversion from cognitively normal to mild cognitive impairment. Results Of 254 participants, 62 (11 clinic, 51 community) progressed to MCI. The clinic-based sample showed an annual conversion rate of 30% (95% CI 17–54%) per person-year, whereas the community-based sample showed a conversion rate of 5% (95% CI 3–6%) per person-year. Risk factors for conversion include clinic based recruitment, being older, lower executive function and worse functional assessment at baseline, and smaller total brain volume. Conclusion and Relevance Older adults who sought out a clinical evaluation, even when they are found to have normal cognition, have increased risk of subsequent development of MCI. Results are consistent with other studies showing subjective cognitive complaints are a risk for future cognitive impairment, but extend such findings to show that those who seek evaluation for their complaints are at particularly high risk. Moreover, these individuals have subtle, but significant differences in functional and cognitive abilities that, in the presence of concerns and evidence of atrophy on by brain imaging, warrant continued clinical follow-up. These risk factors could also be used as stratification variables for dementia prevention clinical trial design.

Factors associated with cognitive impairment in a cohort of older homeless adults: Results from the HOPE HOME study

“…Persons with executive dysfunction might have difficulty completing multi-step commands, organizing their daily schedule, or participating in interactive treatment models such as cognitive behavioral therapy and self-help programs. In addition, executive dysfunction has been associated with a higher risk of progression of cognitive impairment (Chen et al, 2016), functional decline, and elevated mortality (Johnson et al, 2007). …”

Is function in instrumental activities of daily living a useful feature in predicting Alzheimer's disease dementia in subjective cognitive decline?

“…Stogmann et al saw a decreased functional performance in SCD patients compared with controls . Second, in longitudinal analyses, impaired IADL in SCD were associated with higher risk of MCI . However, less information seems to be available regarding AD dementia risk in SCD with regard to IADL function—therefore, we aimed to investigate that in a large sample of cognitively unimpaired older individuals.…”

“…12 Second, in longitudinal analyses, impaired IADL in SCD were associated with higher risk of MCI. 13,14 However, less information seems to be available regarding AD dementia risk in SCD with regard to IADL function-therefore, we aimed to investigate that in a large sample of cognitively unimpaired older individuals. Exclusion criteria were nursing home residence, GP consultation at home, severe illness with an expected fatal outcome within 3 months, German language insufficiency, deafness or blindness, and inability to provide informed consent.…”

Use of an Alzheimer’s disease polygenic risk score to identify mild cognitive impairment in adults in their 50s

“…This criterion is stricter than the more commonly used Jak-Bondi cut-off of >1SD below normative means [21][22][23] because we had a community-based cohort, almost all of whom were in their 50s, which is much younger than MCI samples that typically average 15-20 years older. Thresholds for defining impairment often need to be different depending on expected base rates, and base rates will differ as a function of factors such as community vs. clinic samples or sample age [38,39].…”