Health Care Team Interventions to Reduce Distress Behaviors in Older Adults: A Systematic Review.

OBJECTIVES: This review examines health care team-focused interventions on managing persistent or recurrent distress behaviors among older adults in long-term residential or inpatient health care settings. METHODS: We searched interventions addressing health care worker (HCW) knowledge and skills related to distress behavior management using Ovid MEDLINE, Elsevier Embase, and Ovid PsycINFO from December 2002 through December 2022. RESULTS: We screened 6,582 articles; 29 randomized trials met inclusion criteria. Three studies on patient-facing HCW interactions (e.g. medication management, diagnosing distress) showed mixed results on agitation; one study found no effect on quality of life. Six HCW-focused studies suggested short-term reduction in distress behaviors. Quality-of-life improvement or decreased antipsychotic use was not evidenced. Among 17 interventions combining HCW-focused and patient-facing activities, 0 showed significant distress reduction, 8 showed significant antipsychotic reduction (OR = 0.79, 95%CI [0.69, 0.91]) and 9 showed quality of life improvements (SMD = 0.71, 95%CI [0.39, 1.04]). One study evaluating HCW, patient-, and environmental-focused intervention activities showed short-term improvement in agitation. CONCLUSIONS AND CLINICAL IMPLICATIONS: Novel health care models combining HCW training and patient management improve patient quality of life, reduce antipsychotic use, and may reduce distress behaviors. Evaluation of intervention's effects on staff burnout and utilization is needed.

Novel measures of cognition and function for the AD spectrum in the Novel Measures for Alzheimer's Disease Prevention Trials (NoMAD) project: Psychometric properties, convergent validation, and contrasts with established measures.

INTRODUCTION: This study derived composite scores for two novel cognitive measures, the No Practice Effect (NPE) battery and the Miami Computerized Functional Skills Assessment and Training system for use in early-stage Alzheimer's disease (AD) clinical trials. Their psychometric properties and associations with AD risk markers were compared to those of well-established measures. METHODS: For 291 older adults with healthy cognition or early mild cognitive impairment, Exploratory factor analyses were used to identify the factor structure of the NPE. Factor and total scores were examined for their psychometric properties and associations with AD risk biomarkers. RESULTS: Composite scores from the novel cognitive and functional measures demonstrated better psychometric properties (distribution and test-retest reliability) and stronger associations with AD-related demographic, genetic, and brain risk markers than well-established measures, DISCUSSION: These novel measures have potential for use as primary cognitive and functional outcomes in early-stage AD clinical trials. HIGHLIGHTS: Well-established cognitive tests may not accurately detect subtle cognitive changes. No Practice Effect (NPE) and Computerized Functional Skills Assessment and Training are novel measures designed to have improved psychometric properties. NPE had Executive Function, Cognitive Control/Speed, and Episodic Memory domains. Novel measures had better psychometric properties compared to established measures. Significant associations with Alzheimer's disease biomarkers were found with novel measures.

Effects of APOE ε4 and Neuropathological Diagnoses on Neuropsychiatric Symptoms: Mediation Analyses and Likely Causation in an Integrated National Alzheimer's Coordinating Center Database.

BACKGROUND: In this study, we sought to identify paths from APOE ε4 to neurobehaviors itemized on a neuropsychiatric inventory (Neuropsychiatric Inventory-Questionnaire [NPI-Q]) that involved neuropathologies associated with APOE ε4 (amyloid, tau, cerebral amyloid angiopathy, and Lewy bodies) or cognition mediators (memory or global cognitive status) as well as direct paths from APOE ε4 to neurobehaviors. METHODS: A total of 1199 cases with available neurobehavioral, cognition, and neuropathological data were included. We conducted a series of causal mediation analyses in which APOE ε4 always served as the independent variable, and NPI-Q neurobehavioral items, when included in the mediation analysis, served as the outcome. Neuropathologies or cognition served as mediators. RESULTS: Multiple significant indirect paths from APOE ε4 through neuropathologies to neurobehaviors were identified. More refined analyses indicated that neuritic plaques and Braak stage drove the findings. A significant direct effect of APOE ε4 on memory was also identified. Additionally, Lewy body disease, when treated as an exposure, had a direct effect on hallucinations consistent with features of the disease. CONCLUSIONS: We found strong evidence for partial mediation of NPI-Q symptoms by cognition, suggesting that cognitive limitations may have promoted maladaptive behavior. In addition, neuritic amyloid plaque levels and Braak stage, but not diffuse amyloid plaque extent, were key in NPI-Q-mediated associations, suggesting the possibility that synaptic failure plays an important role in multiple neurobehavioral symptoms in dementia, including psychosis. Finally, we found strong evidence that APOE ε4 may have direct effects on cognition when we used verbal episodic memory but not global cognitive status as an outcome.

Effects of APOE e4 and Neuropathological Diagnoses on Neuropsychiatric Symptoms: Mediation Analyses and Likely Causation in an Integrated NACC Database.

Background: Our goal in this study was to identify paths from APOE e4 to neurobehaviors itemized on a neuropsychiatric inventory that involved neuropathologies associated with e4 (amyloid, tau, cerebral amyloid angiopathy, and Lewy bodies) or cognition mediators (memory or global cognitive status), as well as direct paths from e4 to cognition or neurobehaviors. Methods: A total of 1199 cases with available neurobehavioral, cognition and neuropathological data were included. We then conducted a series of causal mediation analyses in R in which e4 always served as the independent variable and Neuropsychiatric Inventory (NPI) neurobehavioral items, when included in the mediation, the outcome. Neuropathologies or cognition served as mediators. Results: Multiple significant indirect paths from e4 through neuropathologies to neurobehaviors were identified. More refined analyses indicated that neuritic plaques and Braak stage, but not extent of diffuse amyloid plaques, drove the findings. A significant direct effect of e4 to memory was also identified. Additionally, Lewy body disease, when treated as an exposure, had a direct effect on hallucinations in keeping with known features of the disease. Conclusions: We found strong evidence for partial mediation of NPI symptoms by cognition, suggesting that cognitive limitations that may have influenced understanding (or misunderstanding) the environment with impacts on maladaptive behavior. In addition, neuritic amyloid plaque levels and Braak stage, but not diffuse amyloid plaque extent, were key in NPI mediated associations suggesting the possibility that synaptic failure play an important role in multiple neurobehavioral symptoms in dementia, including psychosis. Last, we found strong evidence that e4 may have direct effects on cognition when we used verbal episodic memory as an outcome, suggesting that medial temporal regions that support memory may be sensitive to non-amyloidogenic and non-tau related pathophysiological processes.

Apolipoprotein E Genotype e2: Neuroprotection and Its Limits.

In this review, we comprehensively, qualitatively, and critically synthesized several features of APOE-e2, a known APOE protective variant, including its associations with longevity, cognition, and neuroimaging, and neuropathology, all in humans. If e2's protective effects-and their limits-could be elucidated, it could offer therapeutic windows for Alzheimer's disease (AD) prevention or amelioration. Literature examining e2 within the years 1994-2021 were considered for this review. Studies on human subjects were selectively reviewed and were excluded if observation of e2 was not specified. Effects of e2 were compared with e3 and e4, separately and as a combined non-e2 group. Our examination of existing literature indicated that the most robust protective role of e2 is in longevity and AD neuropathologies, but e2's effect on cognition and other AD imaging markers (brain structure, function, and metabolism) were inconsistent, thus inconclusive. Notably, e2 was associated with greater risk of non-AD proteinopathies and a disadvantageous cerebrovascular profile. We identified multiple methodological shortcomings of the literature on brain function and cognition that could have contributed to inconsistent and potentially misleading findings. We make careful interpretations of existing findings and provide directions for research strategies that could effectively examine the independent and unbiased effect of e2 on AD risk.

Telehealth for the Longitudinal Management of Chronic Conditions: Systematic Review.

BACKGROUND: Extensive literature support telehealth as a supplement or adjunct to in-person care for the management of chronic conditions such as congestive heart failure (CHF) and type 2 diabetes mellitus (T2DM). Evidence is needed to support the use of telehealth as an equivalent and equitable replacement for in-person care and to assess potential adverse effects. OBJECTIVE: We conducted a systematic review to address the following question: among adults, what is the effect of synchronous telehealth (real-time response among individuals via phone or phone and video) compared with in-person care (or compared with phone, if synchronous video care) for chronic management of CHF, chronic obstructive pulmonary disease, and T2DM on key disease-specific clinical outcomes and health care use? METHODS: We followed systematic review methodologies and searched two databases (MEDLINE and Embase). We included randomized or quasi-experimental studies that evaluated the effect of synchronously delivered telehealth for relevant chronic conditions that occurred over ≥2 encounters and in which some or all in-person care was supplanted by care delivered via phone or video. We assessed the bias using the Cochrane Effective Practice and Organization of Care risk of bias (ROB) tool and the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation. We described the findings narratively and did not conduct meta-analysis owing to the small number of studies and the conceptual heterogeneity of the identified interventions. RESULTS: We identified 8662 studies, and 129 (1.49%) were reviewed at the full-text stage. In total, 3.9% (5/129) of the articles were retained for data extraction, all of which (5/5, 100%) were randomized controlled trials. The CHF study (1/5, 20%) was found to have high ROB and randomized patients (n=210) to receive quarterly automated asynchronous web-based review and follow-up of telemetry data versus synchronous personal follow-up (in-person vs phone-based) for 1 year. A 3-way comparison across study arms found no significant differences in clinical outcomes. Overall, 80% (4/5) of the studies (n=466) evaluated synchronous care for patients with T2DM (ROB was judged to be low for 2, 50% of studies and high for 2, 50% of studies). In total, 20% (1/5) of the studies were adequately powered to assess the difference in glycosylated hemoglobin level between groups; however, no significant difference was found. Intervention design varied greatly from remote monitoring of blood glucose combined with video versus in-person visits to an endocrinology clinic to a brief, 3-week remote intervention to stabilize uncontrolled diabetes. No articles were identified for chronic obstructive pulmonary disease. CONCLUSIONS: This review found few studies with a variety of designs and interventions that used telehealth as a replacement for in-person care. Future research should consider including observational studies and studies on additional highly prevalent chronic diseases.

Adherence to Low-Carbohydrate Diets in Patients with Diabetes: A Narrative Review.

Evidence suggests that low carbohydrate (<130 g/day of carbohydrate) (LCD) and very low carbohydrate, ketogenic diets (typically <50 g/day of carbohydrate) (VLCKD) can be effective tools for managing diabetes given their beneficial effects on weight loss and glycemic control. VLCKD also result in favorable lipid profile changes. However, these beneficial effects can be limited by poor dietary adherence. Cultural, religious, and economic barriers pose unique challenges to achieving nutritional compliance with LCD and VLCKD. We review the various methods for assessing adherence in clinical studies and obstacles posed, as well as potential solutions to these challenges.

Novel approaches to measuring neurocognitive functions in Alzheimer's disease clinical trials.

PURPOSE OF REVIEW: We comprehensively examined recent advancements in developing novel cognitive measures that could significantly enhance detection of outcome changes in Alzheimer's disease clinical trials. Previously established measures were largely limited in their ability to detect subtle cognitive declines in preclinical stages of Alzheimer's disease, particularly due to weak psychometric properties (including practice effects and ceiling effects) and requirement of in-person visits that impacted ascertainment. RECENT FINDINGS: We present novel cognitive measures that were designed to exhibit reduced practice effects and stronger correlations with Alzheimer's disease biomarkers. In addition, we summarized some recent efforts in developing remote testing measures protocols that are aimed to overcome the limitations and inconvenience of in-person testing, and digital phenotyping, which analyses subtle forms of digital behaviour indicative of cognitive phenotypes. We discuss each measure's prognostic accuracy and potential utility in Alzheimer's disease research while also commenting on their limitations. We also describe our study, the Development of Novel Measures for Alzheimer's Disease Prevention Trials (NoMAD), that employed a parallel group design in which novel measures and established measures are compared in a clinical trials armature. SUMMARY: Overall, we believe that these recent developments offer promising improvements in accurately detecting clinical and preclinical cognitive changes in the Alzheimer's disease spectrum; however, further validation of their psychometric properties and diagnostic accuracies is warranted before reliably implementing these novel measures in Alzheimer's disease clinical trials.

Modeling cell-specific dynamics and regulation of the common gamma chain cytokines.

The γ-chain receptor dimerizes with complexes of the cytokines interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21 and their corresponding "private" receptors. These cytokines have existing uses and future potential as immune therapies because of their ability to regulate the abundance and function of specific immune cell populations. Here, we build a binding reaction model for the ligand-receptor interactions of common γ-chain cytokines, which includes receptor trafficking dynamics, enabling quantitative predictions of cell-type-specific response to natural and engineered cytokines. We then show that tensor factorization is a powerful tool to visualize changes in the input-output behavior of the family across time, cell types, ligands, and concentrations. These results present a more accurate model of ligand response validated across a panel of immune cell types as well as a general approach for generating interpretable guidelines for manipulation of cell-type-specific targeting of engineered ligands.

Methyltransferase-like 21C (METTL21C) methylates alanine tRNA synthetase at Lys-943 in muscle tissue.

Protein-lysine methylation is a common posttranslational modification (PTM) throughout the human proteome that plays important roles in diverse biological processes. In humans, there are >100 known and candidate protein lysine methyltransferases (PKMTs), many of which are linked to human diseases. Methyltransferase-like protein 21C (METTL21C) is a PKMT implicated in muscle biology that has been reported to methylate valosin-containing protein/p97 (VCP) and heat shock 70-kDa protein 8 (HSPA8). However, a clear in vitro methyltransferase activity for METTL21C remains yet to be demonstrated, and whether it is an active enzyme that directly methylates substrate(s) in vivo is unclear. Here, we used an unbiased biochemistry-based screening assay coupled to MS, which identified alanine tRNA synthetase 1 (AARS1) as a direct substrate of METTL21C. We found that METTL21C catalyzes methylation of Lys-943 of AARS1 (AARS1-K943me) both in vitro and in vivoIn vitro METTL21C-mediated AARS1 methylation was independent of ATP or tRNA molecules. Unlike for AARS1, and in conflict with previous reports, we did not detect METTL21C methylation of VCP and HSPA8. AARS1-K943 methylation in HEK293T cells depends upon METTL21C levels. Finally, METTL2C was almost exclusively expressed in muscle tissue, and, accordingly, we detected METTL21C-catalyzed methylation of AARS1 in mouse skeletal muscle tissue. These results reveal that AARS1 is a bona fide in vitro substrate of METTL21C and suggest a role for the METTL21C-AARS1 axis in the regulation of protein synthesis in muscle tissue. Moreover, our study describes a straightforward protocol for elucidating the physiological substrates of poorly characterized or uncharacterized PKMTs.

METTL13 Methylation of eEF1A Increases Translational Output to Promote Tumorigenesis.

Increased protein synthesis plays an etiologic role in diverse cancers. Here, we demonstrate that METTL13 (methyltransferase-like 13) dimethylation of eEF1A (eukaryotic elongation factor 1A) lysine 55 (eEF1AK55me2) is utilized by Ras-driven cancers to increase translational output and promote tumorigenesis in vivo. METTL13-catalyzed eEF1A methylation increases eEF1A's intrinsic GTPase activity in vitro and protein production in cells. METTL13 and eEF1AK55me2 levels are upregulated in cancer and negatively correlate with pancreatic and lung cancer patient survival. METTL13 deletion and eEF1AK55me2 loss dramatically reduce Ras-driven neoplastic growth in mouse models and in patient-derived xenografts (PDXs) from primary pancreatic and lung tumors. Finally, METTL13 depletion renders PDX tumors hypersensitive to drugs that target growth-signaling pathways. Together, our work uncovers a mechanism by which lethal cancers become dependent on the METTL13-eEF1AK55me2 axis to meet their elevated protein synthesis requirement and suggests that METTL13 inhibition may constitute a targetable vulnerability of tumors driven by aberrant Ras signaling.

The epigenetic regulator SIRT7 guards against mammalian cellular senescence induced by ribosomal DNA instability.

In the yeast Saccharomyces cerevisiae, genomic instability in rDNA repeat sequences is an underlying cause of cell aging and is suppressed by the chromatin-silencing factor Sir2. In humans, rDNA instability is observed in cancers and premature aging syndromes, but its underlying mechanisms and functional consequences remain unclear. Here, we uncovered a pivotal role of sirtuin 7 (SIRT7), a mammalian Sir2 homolog, in guarding against rDNA instability and show that this function of SIRT7 protects against senescence in primary human cells. We found that, mechanistically, SIRT7 is required for association of SNF2H (also called SMARCA5, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin, subfamily A, member 5), a component of the nucleolar heterochromatin-silencing complex NoRC, with rDNA sequences. Defective rDNA-heterochromatin silencing in SIRT7-deficient cells unleashed rDNA instability, with excision and loss of rDNA gene copies, which in turn induced acute senescence. Mounting evidence indicates that accumulation of senescent cells significantly contributes to tissue dysfunction in aging-related pathologies. Our findings identify rDNA instability as a driver of mammalian cellular senescence and implicate SIRT7-dependent heterochromatin silencing in protecting against this process.

RBM25 is a global splicing factor promoting inclusion of alternatively spliced exons and is itself regulated by lysine mono-methylation.

In eukaryotes, precursor mRNA (pre-mRNA) splicing removes non-coding intron sequences to produce mature mRNA. This removal is controlled in part by RNA-binding proteins that regulate alternative splicing decisions through interactions with the splicing machinery. RNA binding motif protein 25 (RBM25) is a putative splicing factor strongly conserved across eukaryotic lineages. However, the role of RBM25 in global splicing regulation and its cellular functions are unknown. Here we show that RBM25 is required for the viability of multiple human cell lines, suggesting that it could play a key role in pre-mRNA splicing. Indeed, transcriptome-wide analysis of splicing events demonstrated that RBM25 regulates a large fraction of alternatively spliced exons throughout the human genome. Moreover, proteomic analysis indicated that RBM25 interacts with components of the early spliceosome and regulators of alternative splicing. Previously, we identified an RBM25 species that is mono-methylated at lysine 77 (RBM25K77me1), and here we used quantitative mass spectrometry to show that RBM25K77me1 is abundant in multiple human cell lines. We also identified a region of RBM25 spanning Lys-77 that binds with high affinity to serine- and arginine-rich splicing factor 2 (SRSF2), a crucial protein in exon definition, but only when Lys-77 is unmethylated. Together, our findings uncover a pivotal role for RBM25 as an essential regulator of alternative splicing and reveal a new potential mechanism for regulation of pre-mRNA splicing by lysine methylation of a splicing factor.

Hippocampal volume in patients with asthma: Results from the Dallas Heart Study.

INTRODUCTION: Asthma is associated with an increased risk of mild cognitive impairment and dementia. Depression and oral corticosteroid use are associated with atrophy of the hippocampus and are common in asthma. However, minimal neuroimaging data are available in asthma patients. METHODS: We conducted a retrospective analysis of 1,287 adult participants from the Dallas Heart Study, an epidemiological sample of Dallas County residents. Study outcome variables were hippocampal volumes measured by FreeSurfer. ANOVA was used to examine a gender difference in hippocampal volumes. General Linear Models (GLM) were conducted to examine asthma diagnosis association with hippocampal volumes. RESULTS: The prevalence rate of asthma among our study sample was 10.8% with 9.6% in males and 11.7% in females. After controlling for demographic characteristics, participants with asthma had significantly smaller total, right, and left hippocampal volumes than those without asthma. The association of asthma with smaller hippocampal volume was significant among males but not among females. CONCLUSION: Hippocampal volume in a large and diverse sample of adults was significantly smaller in people with asthma as compared to those without asthma. These findings suggest that asthma may be associated with structural brain differences. Thus, medical illnesses without obvious direct neurodegenerative or even vascular involvement can be associated with brain changes. Because the hippocampus is a brain region involved in memory formation, these findings may have implications for treatment adherence that could have important implications for asthma treatment. Study limitations are the reliance on a self-reported asthma diagnosis and lack of additional asthma clinical information.

Nonhistone Lysine Methylation in the Regulation of Cancer Pathways.

Proteins are regulated by an incredible array of posttranslational modifications (PTMs). Methylation of lysine residues on histone proteins is a PTM with well-established roles in regulating chromatin and epigenetic processes. The recent discovery that hundreds and likely thousands of nonhistone proteins are also methylated at lysine has opened a tremendous new area of research. Major cellular pathways involved in cancer, such as growth signaling and the DNA damage response, are regulated by lysine methylation. Although the field has developed quickly in recent years many fundamental questions remain to be addressed. We review the history and molecular functions of lysine methylation. We then discuss the enzymes that catalyze methylation of lysine residues, the enzymes that remove lysine methylation, and the cancer pathways known to be regulated by lysine methylation. The rest of the article focuses on two open questions that we suggest as a roadmap for future research. First is understanding the large number of candidate methyltransferase and demethylation enzymes whose enzymatic activity is not yet defined and which are potentially associated with cancer through genetic studies. Second is investigating the biological processes and cancer mechanisms potentially regulated by the multitude of lysine methylation sites that have been recently discovered.

Rapid excision of massive localized lymphedema of the male genitalia with vessel sealing device.

INTRODUCTION: To present a series of patients who underwent surgical treatment for massive localized lymphedema (MLL) of the male genitalia and explore the utility of the LigaSure hemostatic vessel sealing device (VSD) for resection of advanced cases. MATERIALS AND METHODS: Although conservative and microsurgical treatments have been reported, MLL of the male genitalia requires open surgical resection with primary reconstruction. We reviewed our prospectively maintained database of all lymphedema excisions performed between January 2007 and December 2014 comparing resection with Bovie electrocautery to resection with the LigaSure VSD. Our analysis focused on any significant differences in rate of resection, estimated blood loss (EBL), and recurrence. RESULTS: Nineteen patients with MLL of the male genitalia underwent excision with either LigaSure (8 patients) or conventional Bovie electrocautery (11 patients). Rate of resection was significantly faster with LigaSure compared to Bovie (33.74 g/min versus 5.32 g/min, p = .035). Additionally, estimated EBL per gram of tissue resected was decreased in the LigaSure group (0.41 mL/g versus 0.17 mL/g, p = .057). Two of the 11 Bovie patients (18%) had recurrence of lymphedema requiring repeat resection, while none of the LigaSure patients developed recurrence. CONCLUSIONS: Resection of genital lymphedema using the LigaSure device offers promising results in managing advanced MLL of the male genitalia with the potential for faster resections, less EBL per tissue resected, and a lower rate of recurrence.

Coordination of stress signals by the lysine methyltransferase SMYD2 promotes pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal form of cancer with few therapeutic options. We found that levels of the lysine methyltransferase SMYD2 (SET and MYND domain 2) are elevated in PDAC and that genetic and pharmacological inhibition of SMYD2 restricts PDAC growth. We further identified the stress response kinase MAPKAPK3 (MK3) as a new physiologic substrate of SMYD2 in PDAC cells. Inhibition of MAPKAPK3 impedes PDAC growth, identifying a potential new kinase target in PDAC. Finally, we show that inhibition of SMYD2 cooperates with standard chemotherapy to treat PDAC cells and tumors. These findings uncover a pivotal role for SMYD2 in promoting pancreatic cancer.

A Proteomic Strategy Identifies Lysine Methylation of Splicing Factor snRNP70 by the SETMAR Enzyme.

The lysine methyltransferase (KMT) SETMAR is implicated in the response to and repair of DNA damage, but its molecular function is not clear. SETMAR has been associated with dimethylation of histone H3 lysine 36 (H3K36) at sites of DNA damage. However, SETMAR does not methylate H3K36 in vitro. This and the observation that SETMAR is not active on nucleosomes suggest that H3K36 methylation is not a physiologically relevant activity. To identify potential non-histone substrates, we utilized a strategy on the basis of quantitative proteomic analysis of methylated lysine. Our approach identified lysine 130 of the mRNA splicing factor snRNP70 as a SETMAR substrate in vitro, and we show that the enzyme primarily generates monomethylation at this position. Furthermore, we show that SETMAR methylates snRNP70 Lys-130 in cells. Because snRNP70 is a key early regulator of 5' splice site selection, our results suggest a model in which methylation of snRNP70 by SETMAR regulates constitutive and/or alternative splicing. In addition, the proteomic strategy described here is broadly applicable and is a promising route for large-scale mapping of KMT substrates.

A comparison of genetic variants between proficient low- and high-risk sport participants.

Athletes participating in high-risk sports consistently report higher scores on sensation-seeking measures than do low-risk athletes or non-athletic controls. To determine whether genetic variants commonly associated with sensation seeking were over-represented in such athletes, proficient practitioners of high-risk (n = 141) and low-risk sports (n = 132) were compared for scores on sensation seeking and then genotyped at 33 polymorphic loci in 14 candidate genes. As expected, athletes participating in high-risk sports score higher on sensation seeking than did low-risk sport athletes (P < .01). Genotypes were associated with high-risk sport participation for two genes (stathmin, (P = .004) and brain-derived neurotrophic factor (P = .03)) as well as when demographically matched subsets of the sport cohorts were compared (P < .05); however, in all cases, associations did not survive correction for multiple testing.

Increased patterns of risky behaviours among helmet wearers in skiing and snowboarding.

BACKGROUND: There has been an ongoing debate as to whether wearing helmets in skiing and snowboarding increases the risk tolerance of participants. OBJECTIVE: To investigate the roles of demographic and personality variables, and helmet usage in predicting risk taking behaviours in a cross-sectional sample of intermediate and proficient skiers and snowboarders. METHODS: Risk taking in skiing was measured using a validated 10-item self-report measure which was designated as the outcome variable in a three step hierarchical regression. Independent predictors included age, sex, education, sport, ability, helmet usage, and personality traits that have been associated with risk taking: impulsivity and sensation seeking. RESULTS: In the final regression model, helmet use significantly predicted variance in risk taking (standardized ß=.10, p=.024), and the relationship remained after accounting for variance due to demographic variables and general trait measures. The partial relationship between risk taking and sex, ability, impulsivity, and sensation seeking were also significant (p<.05). CONCLUSION: High sensation seeking, high impulsivity, male sex, and proficiency were associated with increased patterns of risky behaviours in skiers and snowboarders, and after accounting for these factors, helmet use was a significant predictor of risk taking. The relationship between helmet use and risk taking was modest suggesting that the costs of increased risk taking is not likely to outweigh the protective benefits of a helmet.