Association of Daily Step Patterns With Mortality in US Adults

1週間の歩行パターンと死亡リスクの関連を明らかに --週2回しっかり歩くことで健康は維持できるか？--. 京都大学プレスリリース. 2023-03-30.[Importance] Previous studies have shown that individuals who regularly walk, particularly 8000 daily steps or more, experience lower mortality. However, little is known about the health benefits of walking intensively only a few days a week. [Objective] To evaluate the dose-response association between the number of days an individual takes 8000 steps or more and mortality among US adults. [Design, Setting, and Participants] This cohort study evaluated a representative sample of participants aged 20 years or older in the National Health and Nutrition Examination Surveys 2005-2006 who wore an accelerometer for 1 week and their mortality data through December 31, 2019. Data were analyzed from April 1, 2022, to January 31, 2023. [Exposures] Participants were grouped by the number of days per week they took 8000 steps or more (0 days, 1-2 days, and 3-7 days). [Main Outcomes and Measures] Multivariable ordinary least squares regression models were used to estimate adjusted risk differences (aRDs) for all-cause and cardiovascular mortality during the 10-year follow-up, adjusting for potential confounders (eg, age, sex, race and ethnicity, insurance status, marital status, smoking, comorbidities, and average daily step counts). [Results] Among 3101 participants (mean [SD] age, 50.5 [18.4] years; 1583 [51.0%] women and 1518 [49.0%] men; 666 [21.5%] Black, 734 [23.7%] Hispanic, 1579 [50.9%] White, and 122 [3.9%] other race and ethnicity), 632 (20.4%) did not take 8000 steps or more any day of the week, 532 (17.2%) took 8000 steps or more 1 to 2 days per week, and 1937 (62.5%) took 8000 steps or more 3 to 7 days per week. Over the 10-year follow-up, all-cause and cardiovascular deaths occurred in 439 (14.2%) and 148 (5.3%) participants, respectively. Compared with participants who walked 8000 steps or more 0 days per week, all-cause mortality risk was lower among those who took 8000 steps or more 1 to 2 days per week (aRD, −14.9%; 95% CI −18.8% to −10.9%) and 3 to 7 days per week (aRD, −16.5%; 95% CI, −20.4% to −12.5%). The dose-response association for both all-cause and cardiovascular mortality risk was curvilinear; the protective association plateaued at 3 days per week. Different thresholds for the number of daily steps between 6000 and 10 000 yielded similar results. [Conclusions and Relevance] In this cohort study of US adults, the number of days per week taking 8000 steps or more was associated with a lower risk of all-cause and cardiovascular mortality in a curvilinear fashion. These findings suggest that individuals may receive substantial health benefits by walking just a couple days a week

Type 2 Diabetes, Risk of Dementia and Cognitive Decline, and the Competing Risk of Mortality Among Middle-Aged and Older Adults

Type 2 diabetes is highly prevalent and has been linked with an increased risk of dementia and premature mortality. Earlier death among people with diabetes may impact the association between diabetes and dementia. This is particularly important for populations with a high burden of diabetes, including Mexican Americans and African Americans. The objective of this dissertation was to evaluate the association of diabetes with incidence of dementia and cognitive impairment without dementia (CIND) and cognitive decline in late-life among Mexican Americans and in mid-life among African Americans and whites while accounting for the competing risk of mortality. The study populations included: 1) a cohort of dementia-free older Mexican Americans (n=1617) aged 60-98 from the Sacramento Area Latino Study on Aging (SALSA) followed for 10 years beginning in 1998 and 2) a cohort of middle-aged African Americans and whites (n=1886) aged 48-70 from the Atherosclerosis Risk in Communities (ARIC) Study followed for 14 years beginning in 1990. The association between diabetes and incidence of dementia/CIND was examined with competing risk regression models in the SALSA cohort and the association between diabetes and cognitive decline was examined with joint longitudinal-survival models in the SALSA and ARIC cohorts. In the SALSA cohort, Mexican Americans with treated and untreated diabetes had an increased risk of dementia/CIND compared to those without diabetes (HR=2.05, 95% CI: 1.41-2.97 and HR=1.55, 95% CI: 0.93-2.58) after accounting for the competing risk of death. Additionally, Mexican Americans with diabetes experienced modestly accelerated cognitive decline compared to those without diabetes. In the ARIC cohort, earlier onset of diabetes was associated with greater cognitive decline in mid-life among African Americans. No association between diabetes and cognitive decline was observed among whites. These findings provide evidence that the association between diabetes and dementia/CIND among Mexican Americans remains strong after accounting for the competing risk of mortality. The association between diabetes and cognitive decline is less evident. Future research is needed to identify how diabetes treatments influence cognitive decline among people with diabetes

196 COVID-19 Hospitalization and Death by Concentrated Racial/Ethnic and Economic Segregation: Los Angeles County, January 2020-June 2023

OBJECTIVES/GOALS: This study aims to assess associations over time between several area-based indices of concentration at the extremes and COVID-19 hospitalization and death in Los Angeles County, from January 2020 to June 2023. These measures reflect concentrations of racial/ethnic and economic segregation at the census tract level. METHODS/STUDY POPULATION: Indices of concentration at the extremes (ICEs) for economic segregation, racial/ethnic segregation, and a combination of the two were constructed for each Los Angeles County (LAC) census tract, using 2015-2019 ACS data. The index ranges from -1 to 1 and is the number of advantaged households (HH) minus the number of disadvantaged HH over the total number of HH measured. Economic segregation is HH income over $100,000 vs. below$25,000 per year and racial/ethnic segregation defined as White and Non-Hispanic vs. non-White or Hispanic HH. The distribution of index scores was divided into quintiles (Q1-Q5) for all LAC census tracts. Age-adjusted hospitalization and death rates were derived at the census tract level by quarter (QTR) based on Los Angeles County Department of Public Health surveillance data. RESULTS/ANTICIPATED RESULTS: Age-adjusted hospitalization and death rates were consistently higher across all quarters in Q1 (most deprived) vs. Q5 (most privileged) for all ICE measures. For ICE of economic segregation, the age-adjusted hospitalization and death rate ratios between Q1 and Q5 were 2.12 (range: 1.32 - 4.15; peak 2020 QTR2) and 2.02 (range: 1.46 - 3.21; peak 2021 QTR1), respectively. For ICE of racial segregation, the age-adjusted hospitalization and death rate ratio between Q1 and Q5 was 2.03 (range: 1.08 - 3.95; peak 2020 QTR3) and 1.77 (range: 1.03 - 2.80; peak 2021 QTR1). The ICE of economic/racial segregation combined was the highest, with averages of the age-adjusted hospitalization and death rate ratios between Q1 and Q5 being 2.26 (1.16 - 4.43; peak 2020 QTR2) and 1.99 (range: 1.22 - 3.32; peak 2021 QTR1). DISCUSSION/SIGNIFICANCE: This study assesses the impact of geographic segregation based on indices that quantify the concentration of both deprivation, privilege, and racial/ethnic group, demonstrating that segregation and economic deprivation are consistently associated with higher rates of age-adjusted hospitalization and death from COVID-19 in LAC

Diabetes and Cognition

Dementia is a major cause of disability and death among older adults. Those with type 2 diabetes (T2D) are 50-100% more likely to develop dementia than those without T2D, but it is unknown whether this association reflects a causal relationship. Proposed mechanisms through which T2D could cause dementia include the effects of insulin dysregulation and chronic hyperglycemia on features of Alzheimer's disease and macrovascular and microvascular disorders in the brain. More research is needed to elucidate the link between T2D and dementia and identify strategies to maintain cognitive function among people with T2D

Aduhelm, the newly approved medication for Alzheimer's disease: what epidemiologists can learn and what epidemiology can offer

Alzheimer's disease (AD) is a progressive disorder common among older adults and culminating in profound cognitive impairments and high mortality risk. The US Food and Drug Administration (FDA) recently provided accelerated approval for Aduhelm, a medication for AD treatment. Aduhelm has been described as the first disease-modifying treatment for AD but has not been demonstrated to improve patients' cognitive or functional outcomes. In this commentary, we describe why Aduhelm approval was controversial and aspects of the current evidence of special pertinence to epidemiologists. The FDA decision was primarily based on two randomized controlled trials (RCTs), both terminated early, with conflicting findings about the cognitive benefits of Aduhelm. Both RCTs showed important adverse effects of the medication. The FDA cited the documented reduction in brain amyloid, an AD biomarker hypothesized as a surrogate outcome, to justify accelerated approval. Despite lack of racial/ethnic diversity in the RCT participants, concerns about health disparities have been invoked to argue for public funding of this expensive medication. The Centers for Medicare and Medicaid Services will soon make a funding determination for Aduhelm and similar medications. We end by describing how innovative study designs could accelerate post-approval research and evaluate the proposed surrogate outcomes

Ambient Air Pollution, Noise, and Late-Life Cognitive Decline and Dementia Risk

Exposure to ambient air pollution and noise is ubiquitous globally. A strong body of evidence links air pollution, and recently noise, to cardiovascular conditions that eventually may also affect cognition in the elderly. Data that support a broader influence of these exposures on cognitive function during aging is just starting to emerge. This review summarizes current findings and discusses methodological challenges and opportunities for research. Although current evidence is still limited, especially for chronic noise exposure, high exposure has been associated with faster cognitive decline either mediated through cerebrovascular events or resulting in Alzheimer's disease. Ambient environmental exposures are chronic and affect large populations. While they may yield relatively modest-sized risks, they nevertheless result in large numbers of cases. Reducing environmental pollution is clearly feasible, though lowering levels requires collective action and long-term policies such as standard setting, often at the national level as well as at the local level