Association between executive functions and COMT Val108/158Met polymorphism among healthy younger and older adults: A preliminary study.

BACKGROUND AND OBJECTIVES: Genetic variability in the dopaminergic system could contribute to age-related impairments in executive control. In this study, we examined whether genetic polymorphism for catechol-O-methyltransferase (COMT Val158Met) is related to performance on updating, shifting and inhibition tasks. METHODS: We administered a battery of executive tasks assessing updating, shifting and inhibition functions to 45 older and 55 younger healthy participants, and created composite z-scores associated to each function. Six groups were created based on genetic alleles (Val/Val, Val/Met, Met/Met) derived from the COMT gene and age (younger, older). Age and genotype effects were assessed with t-test and ANOVA (p<0.05). RESULTS: A lower performance was observed in the older group for the three executive processes, and more particularly for inhibition. Moreover, older participants homozygous for the Val allele have a lower performance on the inhibition composite in comparison to younger Val/Val. CONCLUSIONS: These results confirm presence of executive performance decrease in healthy aging. With regard to genetic effect, older participants seem particularly disadvantaged when they have a lower baseline dopamine level (i.e., Val/Val homozygous) that is magnified by aging, and when the executive measure emphasize the need of stable representations (as in inhibition task requiring to maintain active the instruction to not perform an automated process).

Differential Associations Between Distinct Components of Cognitive Function and Mobility: Implications for Understanding Aging, Turning and Dual-Task Walking.

OBJECTIVE: Cognition and mobility are interrelated. However, this association can be impacted by the specific facets of cognition and mobility that are measured, and further by the different task conditions, e.g., single- versus dual-task walking, under which these associations are evaluated. Systematically studying the multiple facets of cognitive-mobility associations under both the task conditions is critical because both cognition and mobility change with age and pose significant risks associated with falls, morbidity, and disability. METHODS: Using a cross-sectional, prospective study design, data from 124 healthy adults [mean age (SD) = 61.51 (11.90); mean education (SD) = 15.94 (2.18)] were collected. A comprehensive battery of cognitive tests was administered, and gait was assessed using a small, lightweight, three-axis accelerometer with a gyroscope. ANALYTICAL PLAN: Data were transformed, and only relatively strong relationships survived after strict statistical criteria adjusting for multiple comparisons were applied. Spearman rho correlation coefficients were used to examine the matrix of correlations between the cognitive-motor variables while adjusting for age and gender. RESULTS: Executive functions, processing speed, and language were associated with distinct facets of variability, pace, and asymmetry, especially under the dual-task walking condition. Both turns and transitions were also associated with cognition during the Timed Up and Go Task. CONCLUSION: Our results extend converging evidence of the involvement of executive functions and processing speed in specific aspects of mobility, along with the role of language. The study has important implications for aging in terms of both assessment and rehabilitation of cognition and gait as well as for the emerging dual-tasking theories and the role of the neural pathways involved in mobility.

Epidemiological and biological determinants of Staphylococcus aureus clinical infection in New York State maximum security prisons.

BACKGROUND: Large outbreaks of Staphylococcus aureus (SA) infections have occurred in correctional facilities across the country. We aimed to define the epidemiological and microbiological determinants of SA infection in prisons to facilitate development of prevention strategies for this underserved population. METHODS: We conducted a case-control study of SA infection at 2 New York State maximum security prisons. SA-infected inmates were matched with 3 uninfected controls. Subjects had cultures taken from sites of infection and colonization (nose and throat) and were interviewed via structured questionnaire. SA isolates were characterized by spa typing. Bivariate and multivariable analyses were conducted using conditional logistic regression. RESULTS: Between March 2011 and January 2013, 82 cases were enrolled and matched with 246 controls. On bivariate analysis, the use of oral and topical antibiotics over the preceding 6 months was strongly associated with clinical infection (OR, 2.52; P < .001 and 4.38, P < .001, respectively). Inmates with clinical infection had 3.16 times the odds of being diabetic compared with inmates who did not have clinical infection (P < .001). Concurrent nasal and/or oropharyngeal colonization was also associated with an increased odds of infection (OR, 1.46; P = .002). Among colonized inmates, cases were significantly more likely to carry the SA clone spa t008 (usually representing the epidemic strain USA300) compared to controls (OR, 2.52; P = .01). CONCLUSIONS: Several inmate characteristics were strongly associated with SA infection in the prison setting. Although many of these factors were likely present prior to incarceration, they may help medical staff identify prisoners for targeted prevention strategies.

Concordance between medical records and interview data in correctional facilities.

BACKGROUND: Self- administered questionnaires or interviews and medical records are often used as sources of research data; thus it is essential to evaluate their concordance and reliability. The aim of this paper was to assess the concordance between medical and behavioral data obtained from medical records and interview questionnaires in two correctional facilities. METHODS: Medical record and interview data were compared for 679 inmates from one male and one female maximum security prison between April 2010 and February 2013. Gender non-stratified and gender-stratified analyses were conducted in SPSS to calculate the prevalence and kappa coefficient scores (κ) for medical (e.g., HIV, diabetes, hypertension) and behavioral (e.g., smoking, drug use, tattoos) conditions. Sensitivity/specificity between medical records and interview were calculated in the gender non-stratified data. RESULTS: In the gender non-stratified analysis, κ score for HIV, hepatitis C, diabetes, asthma, and history of tattoos had strong or good concordance (0.66-0.89). Hypertension, renal/kidney disease, cigarette smoking, antibiotic use in the last 6 months, and cocaine use ever were moderately correlated (0.49-0.57). Both history of any illicit drug use ever (0.36) and marijuana use ever (0.23) had poor concordance. Females had higher κ scores and prevalence rates than males overall. Medical conditions were reported more frequently in medical records and behavioral conditions had higher prevalence in interviews. Sensitivity for medical conditions in the combined facility data ranged from 50.0% to 86.0% and 48.2% to 85.3% for behavioral conditions whereas specificity ranged from 95.9% to 99.5% for medical conditions and 75.9% to 92.8% for behavioral conditions. CONCLUSION: Levels of agreement between medical records and self-reports varied by type of factor. Medical conditions were more frequently reported by chart review and behavioral factors more frequently by self-report. Data source used may need to be chosen carefully depending upon the type of information sought.

Task demand influences relationships among sex, clustering strategy, and recall: 16-word versus 9-word list learning tests.

OBJECTIVE: We compared the relationships among sex, clustering strategy, and recall across different task demands using the 16-word California Verbal Learning Test-Second Edition (CVLT-II) and the 9-word Philadelphia (repeatable) Verbal Learning Test (PrVLT). BACKGROUND: Women generally score higher than men on verbal memory tasks, possibly because women tend to use semantic clustering. This sex difference has been established via word-list learning tests such as the CVLT-II. METHODS: In a retrospective between-group study, we compared how 2 separate groups of cognitively healthy older adults performed on a longer and a shorter verbal learning test. The group completing the CVLT-II had 36 women and 26 men; the group completing the PrVLT had 27 women and 21 men. RESULTS: Overall, multiple regression analyses revealed that semantic clustering was significantly associated with total recall on both tests' lists (P<0.001). Sex differences in recall and semantic clustering diminished with the shorter PrVLT word list. CONCLUSIONS: Semantic clustering uniquely influenced recall on both the longer and shorter word lists. However, serial clustering and sex influenced recall depending on the length of the word list (ie, the task demand). These findings suggest a complex nonlinear relationship among verbal memory, clustering strategies, and task demand.

Regional white matter hyperintensity volume, not hippocampal atrophy, predicts incident Alzheimer disease in the community.

BACKGROUND New-onset Alzheimer disease (AD) is often attributed to degenerative changes in the hippocampus. However, the contribution of regionally distributed small vessel cerebrovascular disease, visualized as white matter hyperintensities (WMHs) on magnetic resonance imaging, remains unclear. OBJECTIVE To determine whether regional WMHs and hippocampal volume predict incident AD in an epidemiological study. DESIGN A longitudinal community-based epidemiological study of older adults from northern Manhattan, New York. SETTING The Washington Heights/Inwood Columbia Aging Project. PARTICIPANTS Between 2005 and 2007, 717 participants without dementia received magnetic resonance imaging scans. A mean (SD) of 40.28 (9.77) months later, 503 returned for follow-up clinical examination and 46 met criteria for incident dementia (45 with AD). Regional WMHs and relative hippocampal volumes were derived. Three Cox proportional hazards models were run to predict incident dementia, controlling for relevant variables. The first included all WMH measurements; the second included relative hippocampal volume; and the third combined the 2 measurements. MAIN OUTCOME MEASURE Incident AD. RESULTS White matter hyperintensity volume in the parietal lobe predicted time to incident dementia (hazard ratio [HR] = 1.194; P = .03). Relative hippocampal volume did not predict incident dementia when considered alone (HR = 0.419; P = .77) or with the WMH measures included in the model (HR = 0.302; P = .70). Including hippocampal volume in the model did not notably alter the predictive utility of parietal lobe WMHs (HR = 1.197; P = .049). CONCLUSIONS The findings highlight the regional specificity of the association of WMHs with AD. It is not clear whether parietal WMHs solely represent a marker for cerebrovascular burden or point to distinct injury compared with other regions. Future work should elucidate pathogenic mechanisms linking WMHs and AD pathology.

Challenges and strategies for research in prisons.

In this article, we discuss some of the challenges encountered while conducting research in two maximum security prisons and approaches we found helpful to facilitate the research process through the development of collaborative relationships, the establishment of prison contacts, and the implementation of rigorous research methods. As a result of our experiences, we have been successful at maintaining a high rate of inmate participation (>80%) and a well-functioning multidisciplinary team. The approaches described may be useful to other investigators planning to conduct research in a challenging setting such as prisons.

Staphylococcus aureus oropharyngeal carriage in a prison population.

Throat carriage (42.7%) of Staphylococcus aureus exceeded nasal carriage (35.0%) in 2 New York prisons. Methicillin resistance, primarily due to USA300, was high at both sites; 25% of dually colonized inmates had different strains. Strategies to reduce S. aureus transmission will need to consider the high frequency of throat colonization.