Neurovascular Mechanisms of Cognitive Aging: Sex-Related Differences in the Average Progression of Arteriosclerosis, White Matter Atrophy, and Cognitive Decline.

Arterial stiffness (arteriosclerosis) has been linked to heightened risks for cognitive decline, and ultimately for Alzheimer's disease and other forms of dementia. Importantly, neurovascular outcomes generally vary according to one's biological sex. Here, capitalizing on a large sample of participants with neuroimaging and behavioral data ( N = 203, age range = 18-87 years), we aimed to provide support for a hierarchical model of neurocognitive aging, which links age-related declines in cerebrovascular health to the rate of cognitive decline via a series of intervening variables, such as white matter integrity. By applying a novel piecewise regression approach to our cross-sectional sample to support Granger-like causality inferences, we show that, on average, a precipitous decline in cerebral arterial elasticity (measured with diffuse optical imaging of the cerebral arterial pulse; pulse-DOT) temporally precedes an acceleration in the development of white matter lesions by nearly a decade, with women protected from these deleterious effects until approximately age 50, the average onset of menopause. By employing multiple-mediator path analyses while controlling for sex, we show that age may impair cognition via the sequential indirect effects of arteriosclerosis and white matter atrophy on fluid, but not crystallized, abilities. Importantly, we replicate these results using pulse pressure, an independent index of arterial health, thereby providing converging evidence for the central role of arteriosclerosis as an accelerating factor in normal and pathological aging and identifying robust sex-related differences in the progression of cerebral arteriosclerosis and white matter degradation.

Equal Prevalence of Depression in Men and Women with Parkinson's Disease Revealed by Online Assessment.

OBJECTIVE: Identifying persons needing mental health services is hampered by stigma-related underreporting of symptoms, especially by men. Men with Parkinson's disease (PD) consistently report lower rates of depression than women in in-person studies. We predicted that online anonymity would elicit more gender-based parity in depression endorsement. METHOD: We administered the Beck Depression Inventory-II (BDI-II) online to 344 participants with PD (52% women). Depression was defined as BDI-II score >13 and/or use of antidepressant medications. RESULTS: Overall depression prevalence was consistent with in-person studies, but with no significant difference between men and women. CONCLUSIONS: Online methods may circumvent barriers to depression identification in men with PD.

Perceived stigma and quality of life in Parkinson's disease with additional health conditions.

Background: Parkinson's disease (PD) is associated with perceived stigma and affects quality of life (QoL). Additional health conditions may influence these consequences of PD. Aims: This study assessed the impact of health conditions on perceived stigma and QoL in persons with PD. We hypothesised that individuals with more health conditions would report more stigma and poorer QoL. We also examined the contributions of demographic and clinical characteristics to the correlations between health conditions and perceived stigma/QoL. Methods: We identified 196 eligible participants from the Boston University Online Survey Study of Parkinson's Disease and examined their health history, performance on multiple stigma measures, and scores on the 39-item Parkinson's Disease Questionnaire assessing QoL. Results: At least one health condition was reported by 79% of the sample, with a median of 2 and a range of 0-7 health conditions. More perceived stigma and poorer QoL were associated with thyroid disease, depression, anxiety, and the total number of health conditions. These correlations were related to younger age, less education, and earlier disease onset. Other health conditions (high blood pressure, back/leg surgery, headache, cancer/tumours, and heart disease) were not significantly correlated with stigma or QoL. Conclusions: Having more health conditions, or thyroid disease, depression, or anxiety, was associated with more perceived stigma and poorer QoL, with younger age, less education, and earlier disease onset affecting the associations. It is important to consider the burden of health conditions and how they affect persons with PD with specific clinical characteristics.

A healthy mind in a healthy body: Effects of arteriosclerosis and other risk factors on cognitive aging and dementia.

In this review we start from the assumption that, to fully understand cognitive aging, it is important to embrace a holistic view, integrating changes in bodily, brain, and cognitive functions. This broad view can help explain individual differences in aging trajectories and could ultimately enable prevention and remediation strategies. As the title of this review suggests, we claim that there are not only indirect but also direct effects of various organ systems on the brain, creating cascades of phenomena that strongly contribute to age-related cognitive decline. Here we focus primarily on the cerebrovascular system, because of its direct effects on brain health and close connections with the development and progression of Alzheimer's Disease and other types of dementia. We start by reviewing the main cognitive changes that are often observed in normally aging older adults, as well as the brain systems that support them. Second, we provide a brief overview of the cerebrovascular system and its known effects on brain anatomy and function, with a focus on aging. Third, we review genetic and lifestyle risk factors that may affect the cerebrovascular system and ultimately contribute to cognitive decline. Lastly, we discuss this evidence, review limitations, and point out avenues for additional research and clinical intervention.

Determinants of seat belt use: A regression analysis with FARS data corrected for self-selection.

INTRODUCTION: We develop a methodology to use FARS data as an alternative to NOPUS in estimating seat belt usage. The advantages of using FARS over NOPUS are that (i) FARS is broader because it contains more variables relevant for policy analysis, (ii) FARS allows for easy multivariate regression analysis, and finally, (iii) FARS data is more cost-effective. METHODOLOGY: We apply a binary logit model in our analysis to determine the likelihood of seat belt usage given various occupant, vehicle, and built environment characteristics. Using FARS data, we derive coefficient estimates for categories such as vehicle occupants' age and night time seat belt use that observational surveys like NOPUS cannot easily provide. RESULTS: Our results indicate that policies should focus on passengers (as opposed to drivers), male and young vehicle occupants, and that law enforcement should focus on pick-up trucks, rural roads, and nights. We find evidence that primary seat belt laws are effective. CONCLUSIONS: Although this is primarily a methodological paper, we present and discuss our results in the context of public policy so that our findings are relevant for road safety practitioners, researchers, and policymakers.

Correcting sample selection in FARS data to estimate seatbelt use.

INTRODUCTION: In this paper, we show that FARS data can be a comparable alternative to observational NOPUS data in estimating seat belt use in the United States once we correct for sample selection bias. RESULTS: Based on assumptions of independence for seatbelt choice, we establish a lower and upper bound for seatbelt usage rates, and find that once we correct for sample selection bias, the seatbelt usage estimates from the corrected FARS emerge at least as a comparable alternative to NOPUS estimates. IMPACT ON INDUSTRY: This implies that researchers can use corrected FARS to complement NOPUS, thus being able to utilize the rich cross-sectional details available in FARS data to analyze various relevant research questions.