Does Mild Functional Impairment Predict Dementia in Older Adults With Normal Cognition?

OBJECTIVES: Functional impairment can be an early indicator of cognitive decline. However, its predictive utility in cognitively normal (CN) older adults remains unclear. This study aimed to determine whether mild functional impairment (MFI) in CN older adults could predict incident dementia over 6 years, in addition to assessing its association with cognitive performance. DESIGN: A longitudinal study with a 6-year follow-up. PARTICIPANTS: A cohort of 296 community-dwelling CN older adults. MEASUREMENTS: MFI was defined by cutoffs for impairment on an objective performance-based and/or subjective questionnaire-based functional assessment. Cox regression analysis was conducted to assess the relationship between MFI and risk of incident dementia and cognitive performances over 6 years. Linear regression analysis examined the association between MFI and baseline cognitive performance. RESULTS: There were no significant longitudinal associations between MFI and incident dementia or changes in cognitive performance over 6 years. Defining MFI using both performance-based and informant-reported assessments was predictive of dementia. Cross-sectional analyses demonstrated significant associations between MFI and poorer baseline global cognition and performance in attention, visuospatial ability, and executive functioning. CONCLUSIONS: CN older adults with MFI were not at an increased risk of developing dementia over 6 years. A definition of functional impairment requiring both performance-based and informant-based assessments may be useful in predicting dementia.

White matter brain age as a biomarker of cerebrovascular burden in the ageing brain.

As the brain ages, it almost invariably accumulates vascular pathology, which differentially affects the cerebral white matter. A rich body of research has investigated the link between vascular risk factors and the brain. One of the less studied questions is that among various modifiable vascular risk factors, which is the most debilitating one for white matter health? A white matter specific brain age was developed to evaluate the overall white matter health from diffusion weighted imaging, using a three-dimensional convolutional neural network deep learning model in both cross-sectional UK biobank participants (n = 37,327) and a longitudinal subset (n = 1409). White matter brain age gap (WMBAG) was the difference between the white matter age and the chronological age. Participants with one, two, and three or more vascular risk factors, compared to those without any, showed an elevated WMBAG of 0.54, 1.23, and 1.94 years, respectively. Diabetes was most strongly associated with an increased WMBAG (1.39 years, p < 0.001) among all risk factors followed by hypertension (0.87 years, p < 0.001) and smoking (0.69 years, p < 0.001). Baseline WMBAG was associated significantly with processing speed, executive and global cognition. Significant associations of diabetes and hypertension with poor processing speed and executive function were found to be mediated through the WMBAG. White matter specific brain age can be successfully targeted for the examination of the most relevant risk factors and cognition, and for tracking an individual's cerebrovascular ageing process. It also provides clinical basis for the better management of specific risk factors.

Association of Blood Pressure With Brain Ages: A Cohort Study of Gray and White Matter Aging Discrepancy in Mid-to-Older Adults From UK Biobank.

BACKGROUND: Gray matter (GM) and white matter (WM) impairments are both associated with raised blood pressure (BP), although whether elevated BP is differentially associated with the GM and WM aging process remains inadequately examined. METHODS: We included 37 327 participants with diffusion-weighted imaging (DWI) and 39 630 participants with T1-weighted scans from UK Biobank. BP was classified into 4 categories: normal BP, high-normal BP, grade 1, and grade 2 hypertension. Brain age gaps (BAGs) for GM (BAGGM) and WM (BAGWM) were derived from diffusion-weighted imaging and T1 scans separately using 3-dimensional-convolutional neural network deep learning techniques. RESULTS: There was an increase in both BAGGM and BAGWM with raised BP (P<0.05). BAGWM was significantly larger than BAGGM at high-normal BP (0.195 years older; P=0.006), grade 1 hypertension (0.174 years older; P=0.004), and grade 2 hypertension (0.510 years older; P<0.001), but not for normal BP. Mediation analysis revealed that the association between hypertension and cognitive decline was primarily mediated by WM impairment. Mendelian randomization analysis suggested a causal relationship between hypertension and WM aging acceleration (unstandardized B, 1.780; P=0.016) but not for GM (P>0.05). Sliding-window analysis indicated the association between hypertension and brain aging acceleration was moderated by chronological age, showing stronger correlations in midlife but weaker associations in the older age. CONCLUSIONS: Compared with GM, WM was more vulnerable to raised BP. Our study provided compelling evidence that concerted efforts should be directed towards WM damage in individuals with hypertension in clinical practice.

Social axioms and psychological toll: A study of emotional, behavioral, and cognitive responses across 35 cultures during the COVID-19 pandemic.

The COVID-19 pandemic has significantly affected the psychological well-being of individuals worldwide. Previous research has indicated that values and beliefs, particularly social axioms, are associated with psychological responses during crises. However, most of the studies have focused on specific regions; the impact of social axioms on a global scale remains unclear. We conducted a multinational study comprising stratified samples of 18,171 participants from 35 cultures. Using multilevel modeling, we examined the associations between social axioms, personal worry, normative concerns, trust, and individuals' psychological responses to the pandemic. The results showed that greater personal worry and normative concerns predicted more negative psychological responses. Furthermore, the study also identified significant buffering effects at the societal level, as cultures with higher overall levels of fate control, religiosity, or reward for application exhibited weaker associations between personal worry and negative responses. Our findings reveal the influence of social axioms on psychological responses during the pandemic, with varying effects across cultures. The buffering effects of fate control, religiosity, and reward for application underscore the importance of considering cultural differences and individual variability when examining the impact of social axioms on psychological outcomes.

Associations between fruit and vegetable intakes and incident depression in middle-aged and older adults from 10 diverse international longitudinal cohorts.

BACKGROUND: Emerging observational evidence supports a role for higher fruit and vegetable intake in protecting against the development of depression. However, there is a scarcity of research in older adults or in low- to middle-income countries (LMICs). METHODS: Participants were 7801 community-based adults (mean age 68.6 ± 8.0 years, 55.8 % female) without depression, from 10 diverse cohorts, including four cohorts from LMICs. Fruit and vegetable intake was self-reported via comprehensive food frequency questionnaire, short food questionnaire or diet history. Depressive symptoms were assessed using validated measures, and depression defined applying validated cut-offs. The associations between baseline fruit and vegetable intakes and incident depression over a follow-up period of three to nine years were examined using Cox regression. Analyses were performed by cohort with results meta-analysed. RESULTS: There were 1630 cases of incident depression (21 % of participants) over 40,258 person-years of follow-up. Higher intake of fruit was associated with a lower risk of incident depression (HR 0.87, 95%CI [0.77, 0.99], I2 = 4 %). No association was found between vegetable intake and incident depression (HR 0.93, 95%CI [0.84, 1.04], I2 = 0 %). LIMITATIONS: Diverse measures used across the different cohorts and the modest sample size of our study compared with prior studies may have prevented an association being detected for vegetable intake. CONCLUSIONS: Our study supports a role for fruit, but not vegetable intake in protecting against depression. Research investigating different types of fruits and vegetables using standardised measures in larger cohorts of older adults from low- and middle-income countries is warranted.