Social Determinants of Health, Risk and Resilience against Alzheimer's Disease and Related Dementias: The Healthy Brain Initiative.

Background: Few studies have investigated associations between perceived social determinants of health (SDOH) and Alzheimer's disease and related dementia (ADRD) biomarkers or between SDOH and resilience against ADRD. Objective: To examine associations between perceived and objective SDOH and ADRD-related outcomes. Methods: We used cross-sectional data on≥50-year-olds without dementia in the Healthy Brain Initiative (n = 162). Questionnaires captured trust in neighbors and indices of perceived neighborhood greenspace access, time spent in neighborhood greenspaces, and interpersonal discrimination. Residential addresses were linked to 2021 Area Deprivation Index scores. The Vulnerability Index (VI) is based on 12 dementia risk factors (e.g., age, race/ethnicity, diabetes) and Resilience Index (RI) is based on 6 protective factors (e.g., diet, mindfulness, physical activity). Cognitive measured included number symbol coding task and Montreal Cognitive Assessment. Biomarkers included Aß42/40 and pTau-217/npTau-217, hippocampal and white matter hyperintensity volume, lipoprotein A, and high-sensitivity c-reactive protein. Results: Perceived greater access to greenspaces (estimate = 2.83, 95% CI = 1.40-4.26) and greater time in neighborhood greenspaces were associated with greater RI scores (estimate = 2.30, 95% CI = 1.24-3.35). Reporting greater discrimination (estimate = 0.10, 95% CI = 0.04-0.16) and living in higher deprivation neighborhoods were associated with greater VI scores (estimate = 0.017, 95% CI = 0.003-0.032). Greater discrimination was associated with greater white matter hyperintensity volume (estimate = 0.27, 95% CI = 0.04-0.51). Conclusions: Perceived greenspace access and time spent in greenspaces were associated with resilience against ADRD, and interpersonal discrimination was associated with vulnerability to ADRD. Future work needs to validate perceived SDOH measures, examine associations in racially/ethnic diverse populations, and investigate longitudinal associations between SDOH and ADRD-related biomarkers.

Olfactory dysfunction from acute upper respiratory infections: relationship to season of onset.

BACKGROUND: Acute viral upper respiratory tract infections are the most common cause of chronic olfactory dysfunction. In light of the seasonality of numerous viruses, the question arises as to whether the frequency and magnitude of postviral olfactory disorders (PVODs) are similarly seasonal. We sought to determine whether olfactory deficits due to influenza and non-influenza-related viruses (I-PVODs and NI-PVODs) vary in frequency or magnitude across seasons in a North American population and whether they are more prevalent or produce more severe olfactory dysfunction during colder months when host susceptibility may be increased. METHODS: This was a retrospective study of 587 patients presenting to an academic smell and taste center with either I-PVOD-related or NI-PVOD-related olfactory deficits. Chi-square and analysis of covariance (age = covariate) compared dysfunction prevalence frequencies and scores on the University of Pennsylvania Smell Identification Test (UPSIT) across calendar months and between months with the coldest and warmest air temperatures. RESULTS: For I-PVOD-related cases, both the prevalence and magnitude of smell dysfunction were highest in the colder months. However, for NI-PVOD-related cases, prevalence was higher in warmer months but, paradoxically, the magnitude of dysfunction was higher in colder months. CONCLUSION: This study shows that seasonal variations occur in both the prevalence and magnitude of PVOD-related olfactory deficits in a North American population, and that such variations differ between NI-PVOD and I-PVOD cases. The findings suggest multiple viruses are involved in producing PVOD-related olfactory deficits.