Objective Inadequate immunoregulation and elevated inflammation may be risk factors for posttraumatic stress disorder (PTSD), and microbial inputs are important determinants of immunoregulation; however, the association between the gut microbiota and PTSD is unknown. This study investigated the gut microbiome in a South African sample of PTSD-affected individuals and trauma-exposed (TE) controls, to identify potential differences in microbial diversity or microbial community structure. Methods The Clinician Administered Posttraumatic Stress Disorder Scale for DSM-5 (CAPS-5) was used to diagnose PTSD according to DSM-5 criteria. Microbial DNA was extracted from stool samples obtained from 18 individuals with PTSD and 12 TE control participants. Bacterial 16S ribosomal RNA (rRNA) gene V3/V4 amplicons were generated and sequenced. Microbial community structure, alpha-diversity, and beta-diversity were analyzed; random forest analysis was used to identify associations between bacterial taxa and PTSD. Results There were no differences between PTSD and TE control groups in alpha- or beta-diversity measures (e.g., alpha-diversity, Shannon index, t = 0.386, P = .70; beta diversity, based on analysis of similarities (ANOSIM), Bray Curtis test statistic = −0.033, P = .70); however, random forests analysis highlighted three phyla as important to distinguish PTSD status: Actinobacteria, Lentisphaerae, and Verrucomicrobia. Decreased total abundance of these taxa was associated with higher PTSD CAPS scores (r = −.387, P = .035). Conclusions In this exploratory study, measures of overall microbial diversity were similar among individuals with PTSD and TE controls; however, decreased total abundance of Actinobacteria, Lentisphaerae, and Verrucomicrobia was associated with PTSD status.

BackgroundRecent studies have shown the enhanced diagnostic capability of the waist-to-height ratio (WHtR) over BMI. However, while a structured cutoff hierarchy has been established for BMI, a rigorous analysis to define individuals as obese using the WHtR has not been performed on a sample of American adults. This study attempts to establish a cutoff for the WHtR using metabolic syndrome as the outcome.MethodsThe study sample consisted of individuals that were part of the National Longitudinal Study of Adolescent Health (Add Health). The final sample for analysis consisted of 7 935 participants (3 469 males, 4 466 females) that were complete respondents for the variables of interest at Wave IV. The participants ranged from 24.55-33.60 years. Weighted and unweighted receiver operator characteristics (ROC) analyses were performed predicting metabolic syndrome from the WHtR. Cutoffs were chosen using the Youden index. The derived cutoffs were validated by logistic regression analysis on the Add Health participants and an external sample of 1 236 participants from the National Health and Nutrition Examination Survey (NHANES).ResultsThe ROC analysis resulted in a WHtR cutoff of 0.578 (Youden Index = 0.50) for the full sample of complete respondents, 0.578 (Youden Index = 0.55) for males only, and 0.580 (Youden Index = 0.50) for females only. The area under the curve was 0.798 (95 % CI (0.788, 0.809)) for the full sample of complete respondents, 0.833 (95 % CI (0.818, 0.848)) for males only, and 0.804 (95 % CI (0.791, 0.818)) for females only. Participants in the validation sample with a WHtR greater than the derived cutoff were more likely (Odds Ratio = 9.8, 95 % CI (6.2, 15.3)) to have metabolic syndrome than those that were not.ConclusionA WHtR cutoff of 0.580 is optimal for discriminating individuals with metabolic syndrome in two nationally representative samples of young adults. This cutoff is an improvement over a previously recommended cutoff of 0.5 as well as other cutoffs derived from international samples.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-016-2964-6) contains supplementary material, which is available to authorized users.

Background: Recent studies have associated sport-related concussion with depression and impaired cognitive ability later in life in former professional football players. However, population studies with two 1950s-era cohorts did not find an association between high school football participation and impaired cognition or depressive symptoms in late adulthood. Purpose/Hypothesis: This study assessed whether actual/intended participation in contact sports during adolescence had an adverse effect on participants’ cognition or depressive symptoms in early adulthood. We hypothesized that there would not be an association. Study Design: Cohort study; Level of evidence, 2. Methods: This study used a subsample (n = 10,951) from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a nationally (United States) representative prospective cohort study following participants through 4 waves of data collection from 1994 through 2008. Participants were categorized as actual/intended participation in no sports, noncontact sports only, and contact sports. We constructed 6 multivariate and logistic regression models predicting word recall, number recall, modified Center for Epidemiologic Studies Depression Scale, depression diagnosis, suicide ideation, and suicide attempts at wave IV as a function of sport participation during wave I. Sport participation was treated as a factor with the referent category noncontact sports. This analysis was repeated on a males-only sample (n = 5008). In the males-only analysis, participants were classified as actual/intended participation in no sports, noncontact sports, contact sports other than American football, and American football. The referent category remained noncontact sports. Results: Intention to participate in contact sports was not significantly associated with any of the outcomes in the full-sample analysis. Intention to participate in football was significantly associated with a reduced odds of depression diagnosis in adulthood (odds ratio, 0.70; P = .02) when compared with noncontact sports participation in the males-only sample. Football was not significantly associated with impaired cognitive ability, increased depressive symptoms, or increased suicide ideation. Conclusion: Actual/intended participation in contact sports during adolescence did not adversely affect Add Health participants’ cognition or depressive symptoms in young adulthood.

IMPORTANCE Concussion on university campuses is a significant health problem. Characterizing the incidence of concussion on college campuses may inform education and resource allocation policy at student health care centers. OBJECTIVES To establish a measure of concussion incidence among collegiate undergraduate students and to describe characteristics associated with concussion incidence, including sex, cause, and month. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study included data from 3 academic years from August 2015 to April 2018 at a large, public university in the United States. Participants included any undergraduate student or varsity athlete who was diagnosed with at least 1 concussion during the academic year. EXPOSURES Sport-and non-sport-related activities of undergraduate students. MAIN OUTCOMES AND MEASURES Concussion diagnosis. RESULTS Among 954 undergraduate students from the general undergraduate population with at least 1 concussion, including 502 men and 452 women, 1020 concussions were diagnosed in 3 academic years. During 2 academic years, a total of 80 concussions occurred among the varsity athlete population, including 26 men and 54 women. Overall, concussion incidence among both the general undergraduate population and varsity athletes was 132.4 (95% CI, 123.2-142.0) concussions per 10 000 students. Men sustained concussions at a rate of 126.1 (95% CI, 114.1-139.0) concussions per 10 000 students and women sustained concussions at a rate of 140.0 (95% CI, 126.2-155.3) concussions per 10 000 students for the 2016 to 2017 and 2017 to 2018 academic years. Concussion incidence peaked in August at the start of the academic year and the rate of non-sport-related concussions (81.0 [95% CI, 73.9-88.7] concussions per 10 000 students for academic years 2016-2017 and 2017-2018) was higher than the rate of sport-related concussions (51.5 [95% CI, 49.5-57.7] concussions per 10 000 students for academic years 2016-2017 and 2017-2018). CONCLUSIONS AND RELEVANCE This cohort study found concussions to be common among this US collegiate population. While concussion is often associated with sport, the incidence of non-sport-related concussion was higher than that of sport-related concussion throughout the academic year. Additional research is warranted to determine if this incidence measure among undergraduate students is generalizable to other university populations.

SES is related to physical fitness in girls but not in boys. A potential explanation for this is that boys are more likely to engage in vigorous leisure time activity regardless of SES than girls.