Researchers have identified factors that may herald new-onset cognitive impairment in older adults, according to a new study reported in the journal Neurology. They also identified factors that predicted progression of persons with MCI to dementia.

The study recruited 2903 people, aged 65 years or older (average age 76 years) from the Washington Heights-Inwood Columbia Aging Project (WHICAP) who were cognitively normal at the time of their inclusion in the study. They were followed for six years to detect any signs of cognitive impairment, based on subjective problems with memory or thinking skills, objective cognitive impairment in at least one cognitive domain on neuropsychological tests and difficulties in carrying out less than three activities of daily life such as using the phone, shopping and handling medications etc.

At the end of six years, 752 out of the 2903 participants developed mild cognitive impairment (MCI).

Persons with more years of education, those who read more, visited their friends, went for walks or had higher income were less likely to develop cognitive impairment. Participants with more years of education or who engaged in a greater number of 13 separate leisure activities lowered their risk of MCI by 5% for each. On the other hand, persons who had a genetic predisposition (APOE ε4 gene) or many comorbid conditions were at a higher risk of developing MCI.

Around 13% of those with MCI were found to have developed dementia at 2 years follow up, whereas ~30% continued to have MCI, 48% no longer fulfilled the criteria for MCI, while ~10% showed a decline in their daily functioning but did not qualify to be classified as either MCI or dementia i.e., “their daily function declined, but their neuropsychological test scores remained mildly impaired, not yet meeting dementia criteria”.

Among those with MCI, progression to dementia was influenced by factors such as symptoms of depression, use of antidepressants, APOE ε4 and multidomain MCI. 18% of those who developed dementia were on antidepressants versus 7% of those who continued to have MCI and 6% of those who did not meet MCI criteria.

Persons who developed MCI had 9.9 years of education vis-à-vis 7 years for those who developed dementia and 11.5 years for those who did not develop MCI. In a similar manner, persons who developed dementia took part in 5.8 leisure activities; those who had MCI indulged in 7.4 leisure activities, while those who did not develop MCI were engaged in 7.5 leisure activities suggesting that participation in fewer leisure activities precedes decrease in activities of daily life.

This study had defined risk factors for new onset of MCI, both modifiable and non-modifiable. It has also delineated factors that influence progression of MCI to dementia and suggests that not all persons with MCI go on to develop dementia. Hence, These findings will help clinicians identify cognitively normal older adults at risk for dementia who benefit from preventive or intervention strategies.

Reference

1. Angevaare MJ, et al. Predictors of incident mild cognitive impairment and its course in a diverse community-based population. Neurology. 2021 Dec 1;10.1212/WNL.0000000000013017. doi: 10.1212/WNL.0000000000013017.