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54 The Differential Impact of Genetic Moderators on the Relationship Between Depression and Cognition
- Mia L. Delgadillo, Eliza Morgan, Nesha Harper, Aidan Boese, Jennifer K Fairchild
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 659-660
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Objective:
Depression has a well-established negative effect on cognitive functioning. Variations in the apolipoprotein e (APOE) and brain-derived neurotrophic factor (BDNF) genes likely contribute to this relationship. APOE4 and the BDNF Val66Met polymorphism are independently associated with late-life depression and cognitive dysfunction. The current study investigated the moderating effects of APOE4 and BDNFMet (i.e., the presence of the BDNF Val66Met polymorphism) on the relationship between depression and cognitive functioning in older adults.
Participants and Methods:The sample included 103 older adults drawn from two clinical trials who were recruited from the VA Palo Alto Health Care System (VAPAHCS) and the Stanford/VA Alzheimer’s Disease Center. Depression was diagnosed using the Mini Neuropsychiatric Interview for the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV). The presence of an APOE4 and BDNFMet allele were dichotomized (i.e., yes/no) and determined using venipuncture. A comprehensive neuropsychological battery was used to assess attention (RAVLT Trial 1, WAIS-IV DSF), processing speed (TMTA, SDMT, Stroop Word, Stroop Color), working memory (WAIS-IV DSB, DSS), visuospatial functioning (JLO), language (VNT), memory (RAVLT Delayed Recall, WMS-IV Logical Memory II), and executive function (TMTB, Stroop Color-Word). Separate moderation analyses were conducted with depression as the predictor and APOE4 or BDNFMet status as the moderator using the SPSS PROCESS macro v4.0. Age was a covariate for models with processing speed, memory, language, and executive function as outcome variables.
Results:Participants were largely male (93%) and White (75%). Ten percent met criteria for depression, 26% were APOE4 carriers, and 32% were BDNFMet carriers. The overall model examining depression, APOE4, and memory was significant (p < .01, R2 = .14). Depression was associated with lower memory performance (p < .05), however, APOE4 was not a significant moderator (p > .05). Similarly, the overall model examining depression, APOE4, and language was also significant (p < .05, R2 = .10). While the direct effects of depression and APOE4 on language were nonsignificant (p > .05), there was a significant two-way interaction between APOE4 and depression (p = .03). The overall model with depression, BDNFMet, and memory was significant (p < .001, R2 = .18). While neither depression nor BDNFMet had significant direct effects on memory (p > .05), a two-way interaction emerged between depression and BDNFMet (p = .05). Simple slopes analyses were used to further investigate significant interactions. Depression, APOE4, and BDNFMet did not significantly impact attention, processing speed, working memory, visuospatial functioning, or executive function, and no significant interactions were noted among variables. BDNFMet had no direct impact on language.
Conclusions:APOE4 and BDNFMet were found to differentially moderate the relationship between depression and cognition. Specifically, APOE4 carriers with depression had worse language performance compared to those who were healthy, depressed, or APOE4 carriers. BDNFMet carriers with depression performed worse on measures of memory compared to those who were healthy, depressed, or BDNFMet carriers. The treatment of depression in APOE4 and BDNFMet carriers may reduce associated cognitive impairments. Limitations and future implications are also discussed.
3 Body Mass Index Partially Mediates Gait Speed and Executive Functioning in Older Adults
- Aidan Boese, Mia Delgadillo, Nesha Harper, Kaci Fairchild
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 319-320
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Objective:
Gait speed is associated with poorer executive functioning performance in older adults such that individuals with slower gait speed have shown declines in cognitive flexibility and set-shifting. Body mass index (BMI) is associated with sedentary lifestyles and slower gait speed, and has demonstrated negative effects on executive set-shifting in this population. However, the interaction between gait speed, BMI, and executive functioning has yet to be examined. The purpose of this study is to investigate the potential mediating effect of BMI on the negative relationship between gait speed and executive functioning in older adults.
Participants and Methods:The sample included 154 community-dwelling older adults drawn from two clinical trials. Participants were recruited from the VA Palo Alto Health Care System and Stanford/VA Alzheimer’s Disease Research Center. Gait speed was measured using the six-minute walk test, with longer distances representing faster gait speeds. Weight and height were used to calculate BMI. Each participant completed the Trail Making Test Part B (TMTB), which was used to measure executive functioning. A simple mediation analysis was performed using SPSS PROCESS Macro version 3.5. The outcome variable for the analysis was TMTB completion times. The predictor variable was gait speed, and the mediator variable was BMI. Age was entered as a covariate. We hypothesized that gait speed will negatively predict time to completion on the executive functioning task. We also hypothesized that BMI will mediate this relationship.
Results:The analysis found that gait speed negatively predicted executive functioning scores (b = -.12, p = .02). The overall mediation model was statistically significant (F(3,150) =9.17, p < .001). Gait speed and age negatively predicted BMI (p < .001). BMI was a significant predictor of executive functioning (p = .001). The direct effect of gait speed on executive functioning remained significant after including BMI in the model (p < .001), which suggests that BMI partially mediated the relationship between gait speed and executive functioning. The indirect effect of the model when including BMI was tested using the bootstrap estimation approach with 5,000 samples, and was found to be significant (95% CI [.03,.11]), indicating that mediation did occur in the analysis.
Conclusions:BMI partially mediated the relationship between gait speed and executive set-shifting. Thus, the path by which gait speed predicted executive functioning abilities was partially attributable to BMI, one measure of obesity. This finding suggests that older adults with slower gait speeds may have poorer executive function partially due to greater BMI. Given the importance of executive functions on independence and well-being in older adulthood, management of BMI could lead to improved functioning and quality of life. Interventions to decrease weight in older adults is likely to result in several positive health outcomes, and these results suggest that they may also promote important cognitive processes.
14 The Impact of Visual Attention and Impulsivity on Disinhibited Eating Behaviors in Older Adults
- Eliza Morgan, Nesha Harper, Adriana Savettiere, Sheila Mae Thompson, J. Kaci Fairchild
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, p. 328
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Objective:
Although the relationship between visual attention, impulsivity, and cognitively restrained eating patterns has been established in previous research, less is known about the relationship of cognitive processes and disinhibited eating patterns in older adults. Research postulates that disinhibited eating behaviors may be associated with stress, limited emotional capacity, anxiety, and impulsivity. The current study investigated impulsivity as a potential mediator of the relationship between visual attention and disinhibited eating in older veterans.
Participants and Methods:This study included 101 Veterans who were screened as part of a larger study assessing the impact of multi-modal activity-based interventions on brain health in older adulthood. The sample included largely White (76%), male (94%) Veterans aged 54 to 88 (M = 70.1, SD 8.9). The Three-Factor Eating Questionnaire was used to assess daily disinhibited eating patterns, and attentional impulsivity was assessed with the Barratt Impulsiveness Scale. Visual attention was evaluated using the Stroop Color Word Test (Color Trial). Mediation analyses were conducted using the SPSS PROCESS Macro. The outcome variable for analysis was disinhibited eating. The predictor variable was visual attention. The mediator variable was impulsivity. Body mass index (BMI) was included as a covariate as it was significantly associated with the predictor and outcome variables.
Results:The indirect effect of visual attention on disinhibited eating was found to be statistically significant (effect = 0.06, 95%: 0.02, 0.12)
Conclusions:Attentional impulsivity appears to mediate the relationship between visual attention and disinhibited eating behaviors. This finding extends the current literature about the relationship between visual attention, impulsivity, and other eating patterns (e.g., cognitively restrained eating) in older adults. Exploring this relationship helps us better understand the impact of eating habits through the aging process. Caregivers and older adults should be informed about the impact of increased impulsivity on disinhibited eating behaviors, especially in those with limited visual attention processes. Further understanding of the neurobiological impact of eating behaviors on cognition in older adulthood may assist in developing awareness about the importance of healthy eating patterns when considering brain health in the aging process.