The journals of gerontology. Series A, Biological sciences and medical sciences最新文献

Background: Extreme temperatures are associated with negative health outcomes, in particular for older adults with pre-existing conditions. While climate change is expected to increase exposure to temperature levels that are detrimental for health, little is known about how dementia shapes vulnerability to extreme temperatures.

Methods: We leveraged repeated quarterly individual-level health claims from 2004 to 2019 on 250,000 individuals in Germany aged 50 years and above with information on key neurodegenerative diseases such as dementia. We linked data on the location of residence of these individuals with high resolution gridded meteorological data. In our empirical analysis, we applied an individual-level Fixed Effects model to estimate how temperature affects the single patient's probability of hospitalization and death, adjusted for seasonality and comorbidities.

Results: Our findings reveal that heat and cold exposure increase the risk of death. Conversely, the association between extreme temperatures and hospital admissions is more nuanced showing an increase only with cold exposure. Stratifying the analysis by individuals affected by dementia, we observe heat to increase mortality only for individuals with dementia and cold to determine an 8 times larger impact on them and a larger increase in hospitalization. Also, we observe individuals aged above 80 and with dementia do be the most at risk of death with exposure to cold and in particular heat.

Conclusion: Our study contributes to the growing body of evidence on the health impacts of climate change and emphasizes the need for targeted strategies to protect vulnerable groups, particularly patients with dementia, from adverse temperature effects.

Background: This study examined the longitudinal relationship between cumulative socioeconomic status (SES) risk and serum neurofilament light chain (NfL) levels to better understand the association between social factors and a biomarker of neurodegeneration.

Methods: We used data from the Family and Community Health Study, collecting psychosocial and blood data at 2 waves (2008) and (2019) from 254 Black Americans (43 males and 211 females). Blood samples were analyzed at each wave for serum NfL concentrations. Regression analysis and mixed-effect modeling examined relationships between cumulative SES risk and serum NfL, controlling for covariates and assessing time effects.

Results: Utilizing 11-year longitudinal data, serum NfL levels increased with age. Higher cumulative SES risk at baseline correlated with elevated serum NfL at the 11-year follow-up and predicted a greater increase in NfL levels. Clinically, NfL is a sensitive biomarker for axonal injury and neurodegeneration, commonly used to detect early and preclinical stages of conditions such as Alzheimer's disease, multiple sclerosis, and other neurodegenerative disorders.

Conclusions: Our results suggest that exposure to cumulative SES risk among Black adults may contribute to elevated levels of NfL, indicating potential early neurodegeneration. Given the established role of NfL in detecting neurodegenerative processes, these findings underscore the importance of interventions that bolster social safety nets and social connectedness to enhance brain health and mitigate neurodegenerative risks.

Background: Reversible short-term fluctuations in the frailty index (FI) are often thought of as representing only noise or error. Here, we assess (i) the size and source of short-term FI fluctuations, (ii) variation across sociodemographic characteristics, (iii) association with chronic diseases, (iv) correlation with age, frailty level, frailty change, and mortality, and (v) whether fluctuations reflect discrete health transitions.

Methods: Nationwide, biweekly longitudinal data from 426 community-dwelling older adults (70+) were collected in the FRequent health Assessment In Later life (FRAIL70+) study using a measurement burst design (5 122 repeated observations, median of 13 repeated observations per person). We calculated the intraindividual standard deviation of the FI and used location-scale mixed regression models.

Results: Mean intraindividual standard deviation was 0.04 (standard deviation = .03). Fluctuations were driven foremost by cognitive problems, somatic symptoms, and limitations in instrumental and mobility-related activities of daily living. Short-term fluctuations correlated with higher FI levels (r = 0.62), 1-year FI change (r = 0.26), and older age (+3% per year). Older adults who took to bed due to a health problem (+50%), those who had an overnight hospital stay (+50%), and those who died during follow-up (+44%) exhibited more FI fluctuations.

Conclusions: Short-term FI fluctuations were neither small nor random. Instead, as older adults become frailer, their measured health also becomes more unstable; hence, short-term fluctuations in overall health status can be seen as a concomitant phenomenon of the aging process. Researchers and clinicians should be aware of the existence of reversible fluctuations in the FI over weeks and months and its consequences for frailty monitoring.

Type H vessels have been proven to couple angiogenesis and osteogenesis. The decline of type H vessels contributes to bone loss in the aging process. Aging is accompanied by the accumulation of advanced oxidation protein products (AOPPs). However, whether AOPP accumulation is involved in age-related decline of type H vessels is unclear. Here, we show that the increase of AOPP levels in plasma and bone was correlated with the decline of type H vessels and loss of bone mass in old mice. Exposure of microvascular endothelial cells to AOPPs significantly inhibited cell proliferation, migration, and tube formation; increased NADPH oxidase activity and excessive reactive oxygen species generation; upregulated the expression of vascular cell adhesion molecule-1 and intercellular cell adhesion molecule-1; and eventually impaired angiogenesis, which was alleviated by redox modulator N-acetylcysteine and NADPH oxidase inhibitor apocynin. Furthermore, reduced AOPP accumulation by NAC treatment was able to alleviate significantly the decline of type H vessels, bone mass loss, and deterioration of bone microstructure in old mice. Collectively, these findings suggest that AOPPs accumulation contributes to the decline of type H vessels in the aging process, and illuminate a novel potential mechanism underlying age-related bone loss.

Introduced in 2010, the subdiscipline of gerontologic biostatistics was conceptualized to address the specific challenges of analyzing data from clinical research studies involving older adults. Since then, the evolving technological landscape has led to a proliferation of advancements in biostatistics and other data sciences that have significantly influenced the practice of gerontologic research, including studies beyond the clinic. Data science is the field at the intersection of statistics and computer science, and although the term "data science" was not widely used in 2010, the field has quickly made palpable effects on gerontologic research. In this Review in Depth, we describe multiple advancements of biostatistics and data science that have been particularly impactful. Moreover, we propose the subdiscipline of "gerontologic biostatistics and data science," which subsumes gerontologic biostatistics into a more encompassing practice. Prominent gerontologic biostatistics and data science advancements that we discuss herein include cutting-edge methods in experimental design and causal inference, adaptations of machine learning, the rigorous quantification of deep phenotypic measurement, and analysis of high-dimensional -omics data. We additionally describe the need for integration of information from multiple studies and propose strategies to foster reproducibility, replicability, and open science. Lastly, we provide information on software resources for gerontologic biostatistics and data science practitioners to apply these approaches to their own work and propose areas where further advancement is needed. The methodological topics reviewed here aim to enhance data-rich research on aging and foster the next generation of gerontologic researchers.

Background: Climate change is expected to disrupt weather patterns across the world, exposing older adults to more intense and frequent periods of hot weather. Meanwhile, lab-based studies have established a causal relationship between ambient temperature and cognitive abilities, suggesting the expected rise in temperature may influence older adults' cognitive functioning. Nevertheless, it is not clear whether, and to what extent, the temperature variations in older adults' own homes - which unlike lab settings is under their control - influence their cognitive functioning. Our objective was to provide proof-of-concept that home ambient temperature influences self-reported ability to maintain attention in older adults.

Methods: We conducted a longitudinal observational study; continuously monitoring the home ambient temperature and self-reported difficulty keeping attention for 12 months in a cohort of community-dwelling older adults living in Boston, MA.

Participants: 47 adults aged 65 and older.

Results: We observed a U-shaped relationship between home ambient temperature at the time of assessment and the odds ratio (OR) of reporting difficulty keeping attention such that the OR was lowest between 20 - 24 ˚C and doubled when moving away from this range by 4 ˚C in either direction.

Discussion: Our results suggest that even under the current climate a considerable portion of older adults encounter indoor temperatures detrimental to their cognitive abilities. Climate change may exacerbate this problem, particularly among low-income and underserved older adults. Addressing this issue in public health and housing policy is essential to building climate-resiliency in this vulnerable population.

Background: This study tested whether the carriage of the longevity-associated G-allele of FOXO3 SNP rs2802292 (TG/GG) protects against incident coronary artery disease (CAD) in men with hypertension.

Methods: Subjects were American men residing on Oahu having Japanese (n = 5415) or Okinawan (n = 897) ancestry and free of CAD at baseline (1965-1968) when aged 45-68 years.

Results: During the follow-up, there were 1 629 incident CAD cases. Adjusting for age and cardiovascular disease risk factors, the main effect Cox model showed that in men of Japanese ancestry, hypertension was a strong predictor of CAD (hazard ratio [HR] 1.61; 95% confidence interval [CI] 1.44-1.80), p < .0001), but TG/GG genotype was not associated with CAD (HR 0.92; 95% CI = 0.82-1.02; p = .11). A full Cox model showed the interaction of TG/GG with hypertension was significant (β = -0.23, p = .038). Stratified by hypertension status, TG/GG genotype TG/GG had a protective effect against CAD in each group (HR 0.83; 95% CI 0.71-0.96; p = .021 in men of Japanese heritage, and HR 0.66; 95% CI 0.43-1.01; p = .054 in men of Okinawan heritage). No association with CAD was seen in normotensive men having either Japanese (HR 1.04; 95% CI 0.89-1.22; p = .61) or Okinawan (HR 0.95; 95% CI 0.66-1.38; p = .79) heritage.

Conclusions: The present prospective study found that longevity-associated FOXO3 genotype did not independently affect the risk of CAD in all men. Rather, it was associated with protection against incident CAD in men with hypertension. Hypertensive middle-aged men with FOXO3TT genotype may merit particular attention in CAD prevention programs.

Skin autofluorescence (SAF), reflecting advanced glycation end-products' accumulation in tissue, has been proposed as a non-invasive aging biomarker. Yet, SAF has not been compared to well-established blood-based aging biomarkers such as MetaboHealth in association with frailty. Furthermore, no previous study determined the longitudinal association of SAF with frailty. We used 2382 Doetinchem Cohort Study participants' (aged 46.0 to 85.4) cross-sectional data, of whom 1654 had longitudinal SAF measurements. SAF was measured using the AGE reader™. MetaboHealth was calculated on 1H-NMR-metabolomics. Linear regressions were used for the associations of SAF and MetaboHealth on the 36-deficit frailty index and logistic regressions for being pre-frail or frail as determined by the frailty phenotype. Longitudinal associations were determined by an interaction term between age and SAF in a linear mixed model. SAF and MetaboHealth were associated with higher odds of pre-frailty (odd ratios per standard deviation SAF: 1.21(1.10;1.32), MetaboHealth: 1.35(1.24;1.49)) and frailty (SAF: 1.70(1.41;2.06), MetaboHealth: 1.90(1.57;2.32)). When mutually adjusted, both aging biomarkers remained associated with pre-frailty (SAF: 1.16(1.05;1.27), MetaboHealth 1.33(1.21;1.46)) and frailty (SAF: 1.52(1.25;1.85), MetaboHealth: 1.75(1.43;2.14)). Additionally, SAF and MetaboHealth were associated with higher frailty index scores (percentage increase per standard deviation SAF:1.35(1.00;1.70), MetaboHealth: 1.87(1.54;2.20)), also after mutual adjustment (SAF: 1.02(0.68;1.37), MetaboHealth: 1.69(1.35;2.02)). SAF was also longitudinally associated with the frailty index (percentage per unit/year increase 0.12(0.07;0.16)). The mutual independence of SAF and MetaboHealth implies they capture distinct aspects of the aging process. Altogether, these findings emphasize SAF's clinical potential as an age-related decline biomarker, which could be further enhanced when combined with MetaboHealth.

Background: Respite care provides short-term relief for caregivers. Despite efforts to promote respite use among Black caregivers, little is known if disparities in respite use between Black and White dementia caregivers have decreased over time. We examined a trend nationally to see if more recent efforts may have helped reduce disparities in respite use.

Methods: We used a repeated cross-sectional design, with the data from 2015, 2017, and 2021 of the National Health and Aging Trends Study and National Study of Caregiving. Our study sample included 764 (in 2015), 839 (in 2017), and 521 (in 2021) non-Hispanic White and Black caregivers who provided care to older adults living with dementia, representing weighted 5 157 569 (2015), 5 877 997 (2017), and 4 712 144 (2021) dementia caregivers nationally. We conducted logistic regression models to assess the differences in respite use between White and Black caregivers over time.

Results: In 2015, Black dementia caregivers had a respite care use rate 11.6 percentage points (95% CI: -16.9 to -6.4) lower than that of White dementia caregivers. However, both in 2017 and 2021, the difference in the use of respite was not statistically significant, leading to a reduced or no gap in respite use between White and Black dementia caregivers. However, respite use remained low in both groups.

Conclusions: Although the gap in respite use between Black and White dementia caregivers had been gradually narrowed over time, more efforts are needed to encourage more respite use among both groups through targeted efforts to address factors that hinder respite use.

Background: Mounting evidence suggests that cognitive impairment is strongly associated with disability in activities of daily living (ADL disability) and long-term care (LTC) costs. However, studies forecasting future LTC costs often overlook these relationships. Consequently, this study aims to more accurately project future LTC costs in China over the next 20 years by considering the intertwined association between disability and cognitive impairment on future LTC costs.

Methods: Data were from 10 959 adults ≥65 years from the 2005-2018 waves of the Chinese Longitudinal Healthy Longevity Surveys. We used the Markov model to project the population of China and track the transition of older adults in the next 20 years between 4 disability-cognition states. We employed a 2-part model to estimate LTC costs (direct and indirect LTC costs) per capita.

Results: The proportion of disabled older adults with cognitive impairment was projected to increase from 1.4% in 2021 to 3.4% in 2040, while that of those without cognitive impairment was projected to decrease from 4.7% in 2021 to 4.5% in 2040. The direct and indirect LTC costs were projected to increase from 0.3% and 0.2% of gross domestic product (GDP) in 2021 to 1.4% and 0.7% in 2040 for disabled persons without cognitive impairment and from 0.1% and 0.1% of GDP in 2021 to 1.3% and 1.3% in 2040 for those with cognitive impairment, respectively.

Conclusions: Policy-makers could include the assessment of cognition in the LTC needs assessment and allocate more compensation to LTC insurance participants with cognitive impairment.