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Objective: Higher levels of loneliness in older adulthood predict cognitive decline, but research on mediating mechanisms is sparse. We examine multisystemic physiological risk, functional ability, self-rated health, depressive symptoms, and social participation as mediating processes for the association between loneliness and general cognitive ability over a 10-year follow-up in an older adult sample.Methods: Three waves of data from 3,005 individuals (mean intake age: 69.30 (SD: 7.85) years; female = 51.61%) recruited during Wave 1 of the National Social Life, Health, and Aging Project were used to test whether hypothesized mediators collected at the 5-year follow-up explained effects of baseline loneliness on 10-year general cognitive ability.Results: The relationship between baseline loneliness and 10-year general cognitive ability was not mediated by multisystemic physiological risk. Functional ability (b = -0.24, SE = 0.05, p <0.001), self-rated health (b = -0.08, SE = 0.02, p <0.001), depressive symptoms (b= -0.20, SE = 0.05, p <0.001), and social participation (b = -0.03, SE = 0.01, p = 0.016) significantly mediated effects. Indirect effects remained significant after adjusting for demographic covariates and 5-year general cognitive ability, except social participation.Discussion: Loneliness may influence cognitive ability indirectly, signaling waning physical and psychiatric health more proximally correlated with cognitive ability. These mechanisms may serve as targets of intervention for cognitive maintenance in lonely older adults. [ABSTRACT FROM AUTHOR]

It is well documented that memory is heritable and that older adults tend to have poorer memory performance than younger adults. However, whether the magnitudes of genetic and environmental contributions to late-life verbal episodic memory ability differ from those at earlier ages remains unresolved. Twins from 12 studies participating in the Interplay of Genes and Environment in Multiple Studies (IGEMS) consortium constituted the analytic sample. Verbal episodic memory was assessed with immediate word list recall (N = 35,204 individuals; 21,792 twin pairs) and prose recall (N = 3805 individuals; 2028 twin pairs), with scores harmonized across studies. Average test performance was lower in successively older age groups for both measures. Twin models found significant age moderation for both measures, with total inter-individual variance increasing significantly with age, although it was not possible definitively to attribute the increase specifically to either genetic or environmental sources. Pooled results across all 12 studies were compared to results where we successively dropped each study (leave-one-out) to assure results were not due to an outlier. We conclude the models indicated an overall increase in variance for verbal episodic memory that was driven by a combination of increases in the genetic and nonshared environmental parameters that were not independently statistically significant. In contrast to reported results for other cognitive domains, differences in environmental exposures are comparatively important for verbal episodic memory, especially word list learning. • Verbal episodic memory performance is poorer at older ages compared to midlife. • Individual variance in verbal episodic memory shows an increase across age. • Environmental variance unique to individuals is more important than genetic variance. • Genetic variance is greater for remembering a prose passage than a list of words. [ABSTRACT FROM AUTHOR]

Numerous studies have found interactions between socioeconomic status (SES) and the heritability of cognitive ability in samples from the United States, with individuals from lower SES backgrounds showing decreased heritability compared to those reared in higher SES environments. However, nearly all published studies of the Scarr-Rowe interaction have been univariate and cross-sectional. In this study, we sought to maximize statistical power by fitting multivariate models of gene (G) x SES interaction, including longitudinal models. Cognitive ability data collected at up to five time points between ages 7 and 15 years were available for 566 twin pairs from the Louisville Twin Study. We used multilevel and latent factor models to pool intelligence subtest scores cross-sectionally. To examine interactions longitudinally, we fit latent growth curve models to IQ scores. Power analysis results indicated that the multivariate approach substantially boosted power to detect G x SES interaction. The predicted interaction effect was observed at most ages in cross-sectional multivariate analyses. In longitudinal analyses, we found significant G x SES interactions on mean-level (intercept) full scale IQ and performance IQ (p s <.001), but not verbal IQ intercept (p =.08). SES did not significantly moderate the heritability of change in IQ over time (slope). Interaction appeared to be driven by DZ twin correlations decreasing more substantially as a function of higher SES than MZ correlations. • G x SES interaction on intelligence is found across mid-childhood/early adolescence. • The interaction appears to be driven by divergence in DZ twins. • Multivariate methods boost power to detect G x SES interaction. [ABSTRACT FROM AUTHOR]

Abstract Risk for Alzheimer's disease (AD) is affected by multiple factors, including aging, obesity, and low testosterone. We previously showed that obesity and low testosterone independently and interactively exacerbate AD-related outcomes in young adult rodents. The goals of the present study are two-fold: to examine whether the effects of an obesogenic diet differ with increasing age and to determine if testosterone treatment in middle-aged and aged animals mitigates negative effects of the diet. Male brown Norway rats were maintained on control or high-fat diets for 12 weeks beginning in young adulthood, middle age, or advanced age. Separate cohorts of middle-aged and aged animals were treated with testosterone during dietary manipulations. Endpoints included metabolic indices, inflammation, cognitive performance, and neural health outcomes. Aging was associated with poorer outcomes that were generally exacerbated by high-fat diet, especially at middle age. Testosterone treatment was largely without benefit, exerting only subtle effects on a select number of measures. Understanding how the deleterious effects of obesity are affected by advancing age and the ability of protective strategies such as testosterone to reduce these effects may provide significant insight into both the development and prevention of age-related cognitive decline and AD. [ABSTRACT FROM AUTHOR]

The American College of Surgeons requires Level I and II trauma centers to provide brief intervention services to traumatically injured patients who screen positive for alcohol. Despite evidence supporting substantial cost savings and reduced re-injury associated with these services, brief interventions may not be uniformly delivered owing to a variety of demographic, clinical and operational characteristics. To inform service adjustments that may improve the reach of such services, we compared trauma patients who did and did not receive brief alcohol intervention services during their hospitalizations. Electronic medical records of injured patients admitted to a Level I trauma center between September 27, 2013 and March 11, 2014 with a positive blood alcohol concentration (N=189) were coded for demographic and clinical variables. Records of those who did not receive a brief intervention during their admission were reviewed for possible reasons why interventions were not delivered. Of the total sample, 115 patients (60.8%) received brief interventions. Patients who did and did not receive brief interventions did not differ on age, sex, race, blood alcohol concentration at admission, or mechanism of injury, indicating that patient characteristics were unlikely to bias service delivery. Instead, common features of patients who were referred but did not receive SBIRT interventions included admissions lasting fewer than two working days (12.7%) and persistent cognitive impairment following injury (9.0%). These findings align with previous studies suggesting that service reach could be improved by promoting dedicated and flexible staffing and adapting services to allow for SBIRT delivery in follow-up care settings. [ABSTRACT FROM AUTHOR]