Cognitive Reserve Attenuates the Relation between Gastrointestinal Diseases and Subsequent Decline in Executive Functioning

Cognitive impairment in long-COVID and its association with persistent dysregulation in inflammatory markers

Objective

To analyze the potential impact of sociodemographic, clinical and biological factors on the long-term cognitive outcome of patients who survived moderate and severe forms of COVID-19.

Methods

We assessed 710 adult participants (Mean age = 55 ± 14; 48.3% were female) 6 to 11 months after hospital discharge with a complete cognitive battery, as well as a psychiatric, clinical and laboratory evaluation. A large set of inferential statistical methods was used to predict potential variables associated with any long-term cognitive impairment, with a focus on a panel of 28 cytokines and other blood inflammatory and disease severity markers.

Results

Concerning the subjective assessment of cognitive performance, 36.1% reported a slightly poorer overall cognitive performance, and 14.6% reported being severely impacted, compared to their pre-COVID-19 status. Multivariate analysis found sex, age, ethnicity, education, comorbidity, frailty and physical activity associated with general cognition. A bivariate analysis found that G-CSF, IFN-alfa2, IL13, IL15, IL1.RA, EL1.alfa, IL45, IL5, IL6, IL7, TNF-Beta, VEGF, Follow-up C-Reactive Protein, and Follow-up D-Dimer were significantly (p<.05) associated with general cognition. However, a LASSO regression that included all follow-up variables, inflammatory markers and cytokines did not support these findings.

Conclusion

Though we identified several sociodemographic characteristics that might protect against cognitive impairment following SARS-CoV-2 infection, our data do not support a prominent role for clinical status (both during acute and long-stage of COVID-19) or inflammatory background (also during acute and long-stage of COVID-19) to explain the cognitive deficits that can follow COVID-19 infection.

Solving the Puzzle of Cognitive Reserve Effects on Cognitive Decline: The Importance of Considering Functional Impairment

AIMS

We investigated whether the longitudinal relation between cognitive reserve accumulated across the lifespan and rate of cognitive decline over 6 years differed by the individual's degree of functional impairment.

METHODS

We analyzed longitudinal data from 897 older adults (M = 74.33 years) tested on the Trail Making Test (TMT) in 2 waves 6 years apart.

RESULTS

There was a significant interaction of functional impairment with cognitive reserve on latent change in cognitive functioning. Specifically, with no functional impairment in the first wave of assessment, greater cognitive reserve accumulated across the lifespan significantly predicted a reduced cognitive decline over 6 years (i.e., smaller increase in TMT completion time). In contrast, with certain functional impairment (in at least some activities) in the first wave, greater cognitive reserve build-up predicted a steeper cognitive decline (i.e., larger increase in TMT completion time).

CONCLUSION

Individuals with greater cognitive reserve accumulated across the lifespan show a reduced cognitive decline if they still have relatively little functional impairment, while they will show a steeper decline (compared to individuals with less cognitive reserve) as soon as functional impairment becomes substantial.

Cognitive Reserve Mitigates Decline in Executive Functioning Following Hepatobiliary Diseases

Abstract. The cognitive reserve hypothesis postulates that lifelong cognitive stimulation establishes a buffer that is instrumental in maintaining cognitive health. To examine this conceptual proposition in detail, we applied a novel, more general conceptual view that included recent models of vulnerability and examined whether the longitudinal association between hepatobiliary diseases and later decline in executive functioning across 6 years varied by cognitive reserve. For this purpose, we investigated longitudinal data from 897 older individuals ( M = 74.33 years) tested using the Trail Making Test (TMT) in two waves 6 years apart. Individuals reported information on key commonly used indicators of lifelong cognitive reserve build-up (i.e., education, work, and participation in leisure activity) and hepatobiliary diseases. The results revealed a significant interaction of hepatobiliary diseases with participation in leisure activity on latent change in executive functioning. Specifically, only in individuals with little (but not greater) participation in leisure activity did hepatobiliary diseases significantly predict a steeper decline in executive functioning over 6 years (i.e., increases in TMT finishing time). In conclusion, the unfavorable aftereffects of hepatobiliary diseases on a later decline in executive functioning seem to be mitigated in individuals who have built up greater cognitive reserve via participation in leisure activity during their life.