Food Insecurity Is High in a Multi-Site Cohort of Transgender Women Vulnerable to or Living with HIV in the Eastern and Southern United States: Baseline Findings from the LITE Cohort

The prevalence and correlates of food insecurity-the unavailability of food and limited access to it-have not been adequately considered among transgender women (TW), particularly alongside other health-related conditions burdening this population, such as HIV infection. This study examined the prevalence and correlates of food insecurity among TW. Between 2018 and 2020, 1590 TW in the Eastern and Southern U.S. completed a multi-site baseline assessment (socio-behavioral survey and HIV testing). Descriptive statistics were calculated and multivariable Poisson models with robust error variance were used to estimate prevalence ratios and 95% confidence intervals for correlates of food insecurity (dichotomized as sometimes-to-always vs. seldom-to-never running out of food). Eighteen percent of TW were living with HIV and nearly half of participants (44%) reported food insecurity. Correlates of food insecurity included being Black, multiracial, or another race/ethnicity; having < college education, low income, unstable housing, and high anticipated discrimination; and a history of sex work and sexual violence (all p < 0.05). Food insecurity was highly prevalent among TW. Current programs to provide food support do not adequately meet the needs of TW. HIV pr evention and care programs may benefit from addressing food insecurity.

Access to healthcare among transgender women living with and without HIV in the United States: associations with gender minority stress and resilience factors

BACKGROUND

Transgender women (TW) experience significant inequities in healthcare access and health disparities compared to cisgender populations. Access to non-transition related healthcare is understudied among TW. We aimed to assess the association between access to care and gender minority stress and resilience factors among TW living with and without HIV in eastern and southern United States.

METHODS

This study was a cross-sectional analysis of baseline data drawn from a cohort of 1613 adult TW from the LITE Study. The cohort permitted participation through two modes: a site-based, technology-enhanced mode and an exclusively online (remote) mode. Exploratory and confirmatory factor analyses determined measurement models for gender minority stress, resilience, and healthcare access. Structural equation modeling was used to assess the relationships between these constructs. Models were evaluated within the overall sample and separately by mode and HIV status.

RESULTS

Higher levels of gender minority stress, as measured by anticipated discrimination and non-affirmation were associated with decreased access to healthcare. Among TW living with HIV, higher levels of anticipated discrimination, non-affirmation, and social support were associated with decreased healthcare access. Among TW living without HIV in the site-based mode, resilience was positively associated with positive healthcare experiences and inversely associated with barriers to healthcare access. Among TW living without HIV in the online mode, anticipated discrimination was associated with barriers to healthcare access; resilience was positively associated with positive healthcare experiences and inversely associated with barriers to healthcare access.

CONCLUSIONS

Gender minority stress was associated with increased barriers to healthcare access among TW in the US, regardless of HIV status. Resilience factors did not mediate this effect. Interventions aiming to increase healthcare access among TW can be aided by efforts to mitigate drivers of gender minority stress and improve patient experiences in healthcare facilities.

Prevalence of sexually transmitted infections among transgender women living with and without HIV in the eastern and southern United States

BACKGROUND

Data on the epidemiology of sexually transmitted infections (STIs) among transgender women (TGW) with and without HIV are limited.

METHODS

We analyzed baseline data collected from a cohort of adult TGW across 6 eastern and southern US cities between March 2018-August 2020 (n = 1,018). Participants completed oral HIV screening, provided self-collected rectal and urogenital specimens for chlamydia and gonorrhea testing, and provided sera specimens for syphilis testing. We assessed associations with ≥1 prevalent bacterial STI using modified Poisson regression.

RESULTS

Bacterial STI prevalence was high and differed by HIV status: 32% among TGW with HIV and 11% among those without HIV (demographic-adjusted prevalence ratio = 1.91 [95%CI = 1.39-2.62]). Among TGW without HIV, bacterial STI prevalence differed by geographic region, race and ethnicity, and gender identity, and was positively associated with reporting >1 sexual partner, hazardous alcohol use, homelessness, having safety concerns regarding transit to healthcare, and no prior receipt of gender-affirming health services. Among TGW with HIV, older age was inversely associated with bacterial STI.

CONCLUSIONS

TGW had a high prevalence of bacterial STIs. The prevalence and correlates of bacterial STI differed by HIV status, highlighting the unique needs and risks of TGW with and without HIV. Tailored interventions may reduce sexual health-related inequities.

PrEP initiation and discontinuation among transgender women in the United States: a longitudinal, mixed methods cohort study

INTRODUCTION

Transgender women in the United States experience high HIV incidence and suboptimal Pre-exposure prophylaxis (PrEP) engagement. We sought to estimate PrEP initiation and discontinuation rates and characterize PrEP discontinuation experiences among a prospective cohort of transgender women.

METHODS

Using a sequential, explanatory, mixed-methods design, 1312 transgender women at risk for HIV acquisition were enrolled from March 2018 to August 2020 and followed through July 2022 (median follow-up 24 months; interquartile range 15-36). Cox regression models assessed predictors of initiation and discontinuation. In-depth interviews were conducted among 18 participants, including life history calendars to explore key events and experiences surrounding discontinuations. Qualitative and quantitative data were integrated to generate typologies of discontinuation, inform meta-inferences and facilitate the interpretation of findings.

RESULTS

21.8% (n = 286) of participants reported taking PrEP at one or more study visits while under observation. We observed 139 PrEP initiations over 2127 person-years (6.5 initiations/100 person-years, 95% CI: 5.5-7.7). Predictors of initiation included identifying as Black and PrEP indication. The rate of initiation among those who were PrEP-indicated was 9.6 initiations/100 person-years (132/1372 person-years; 95% CI: 8.1-11.4). We observed 138 PrEP discontinuations over 368 person-years (37.5 discontinuations/100 person-years, 95% CI: 31.7-44.3). Predictors of discontinuation included high school education or less and initiating PrEP for the first time while under observation. Four discontinuation typologies emerged: (1) seroconversion following discontinuation; (2) ongoing HIV acquisition risk following discontinuation; (3) reassessment of HIV/STI prevention strategy following discontinuation; and (4) dynamic PrEP use coinciding with changes in HIV acquisition risk.

CONCLUSIONS

PrEP initiation rates were low and discontinuation rates were high. Complex motivations to stop using PrEP did not consistently correspond with HIV acquisition risk reduction. Evidence-based interventions to increase PrEP persistence among transgender women with ongoing acquisition risk and provide HIV prevention support for those who discontinue PrEP are necessary to reduce HIV incidence in this population.

HIV incidence and mortality in transgender women in the eastern and southern USA: a multisite cohort study

BACKGROUND

Epidemiological monitoring of HIV among transgender women is minimal despite prioritisation of this group in the US National HIV/AIDS Strategy (2022-2025). We aimed to estimate HIV incidence in a multisite cohort of transgender women in the eastern and southern USA. Participant deaths were identified during follow-up; thus, we felt it was an ethical imperative to report mortality alongside HIV incidence.

METHODS

In this study, we established a multisite cohort across two modes: a site-based, technology-enhanced mode in six cities (Atlanta, Baltimore, Boston, Miami, New York City, and Washington, DC) and an exclusively digital mode that spanned 72 eastern and southern US cities that matched the six site-based cities based on population size and demographics. Trans feminine adults (≥18 years) who were not living with HIV were eligible and followed up for at least 24 months. Participants completed surveys and oral fluid HIV testing with clinical confirmation. We ascertained deaths through community and clinical sources. We estimated HIV incidence and mortality using the number of HIV seroconversions and deaths, respectively, divided by person-years accumulated from enrolment. Logistic regression models were used to identify predictors of HIV seroconversion (primary outcome) or death.

FINDINGS

Between March 22, 2018, and Aug 31, 2020, we enrolled 1312 participants with 734 (56%) in site-based and 578 (44%) in digital modes. At the 24-month assessment, 633 (59%) of 1076 eligible participants consented to extending participation. 1084 (83%) of 1312 participants were retained at this analysis based on the study definition of loss to follow-up. As of May 25, 2022, the cohort participants had contributed 2730 accumulated person-years to the analytical dataset. Overall HIV incidence was 5·5 (95% CI 2·7-8·3) per 1000 person-years and incidence was higher among Black participants and those living in the south. Nine participants died during the study. The overall mortality rate was 3·3 (95% CI 1·5-6·3) per 1000 person-years, and the rate was higher among Latinx participants. Identical predictors of HIV seroconversion and death included residence in southern cities, sexual partnerships with cisgender men, and use of stimulants. Participation in the digital cohort and seeking care for gender transition were inversely associated with both outcomes.

INTERPRETATION

As HIV research and interventions are increasingly delivered online, differences by mode highlight the need for continued community and location-based efforts to reach the most marginalised transgender women. Our findings underscore community calls for interventions that address social and structural contexts that affect survival and other health concerns alongside HIV prevention.

FUNDING

National Institutes of Health.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Characterizing Arrest and Incarceration in a Prospective Cohort of Transgender Women

This study characterized arrest, incarceration, and risk factors for incident incarceration among transgender women (TW) in the northeastern and southern United States. During semiannual study visits over 24 months in a multicenter cohort study, TW completed HIV testing and self-administered surveys. In total, 1571 TW completed baseline survey; 1,312 HIV-negative TW enrolled in the cohort and contributed 2134.3 person-years to the analysis. At baseline, 37% had been arrested and 21% had been incarcerated. Incident incarceration was 23.4 per 1,000 person-years (95% confidence interval [CI]: 16.9-29.9). Sex work was significantly associated with baseline and incident incarceration (p < .01). A history of incarceration at enrollment was the strongest predictor of incident incarceration (adjusted odds ratio [aOR] 6.99; 95% CI: 3.43-14.24). Living in the South (aOR 2.69, 95% CI: 1.22-5.93), income below the federal poverty level (aOR 2.65 95% CI: 3.43-14.24), and having a recent partner who had been incarcerated (aOR 2.62, 95% CI: 1.20-5.69) also increased the odds of incident incarceration in multivariable modeling. Structural interventions to reduce poverty and decriminalize sex work have the potential to reduce incarceration rates among TW.

Multilevel Determinants of Rapid Antiretroviral Treatment Implementation and Demand in Miami-Dade County

BACKGROUND

Rapidly linking newly diagnosed HIV patients to antiretroviral treatment (ART) is the best practice for achieving optimal treatment outcomes, including viral suppression. However, rapid ART implementation varies throughout the United States, highlighting the importance of identifying rapid ART implementation determinants in US HIV epicenters, such as Miami-Dade County (MDC).

METHODS

Clinic focus groups (N = 4 clinics) and patient interviews (N = 31 recently diagnosed patients) systematically and qualitatively assessed rapid ART implementation determinants in MDC. Independent coders analyzed focus groups and interviews using a directed content analysis approach guided by the Consolidated Framework for Implementation Research.

RESULTS

For clinic stakeholders, key rapid ART implementation determinants included the following: complexity and adaptability (innovation characteristics); networks between clinics and patient needs rooted in structural inequities (outer setting); leadership and available resources (inner setting); staff/provider flexibility (characteristics of individuals); and appointing patient navigators and champions (process). For patients, key determinants included complexity and relative advantage of rapid treatment (innovation characteristics); patient needs and clinic networks (outer setting); provider knowledge and skills (inner setting); provider warmth and affirmation (characteristics of individuals); and need for improved outreach (process).

CONCLUSIONS

Multilevel factors impact clinic implementation and patient demand for rapid ART in MDC. Informed by these factors, we identified potential implementation strategies to enhance rapid ART implementation throughout MDC. These implementation strategies can be tested in an implementation trial, enhancing the toolkit of strategies to ensure that evidence-based tools, particularly rapid ART, are readily available to the most impacted communities.

Perceived HIV Acquisition Risk and Low Uptake of PrEP Among a Cohort of Transgender Women With PrEP Indication in the Eastern and Southern United States

INTRODUCTION

Preexposure prophylaxis (PrEP) is effective in preventing HIV among adherent users. However, PrEP uptake among transgender women is low, and current prescribing guidelines from the Centers for Disease Control and Prevention (CDC) are not specific to transgender women. Self-perceived risk of HIV among those who are PrEP-indicated is not well understood.

METHODS

This cross-sectional analysis included 1293 transgender women screened at baseline from March 2018 to May 2020 for a multisite, prospective cohort study. We compared the prevalence of PrEP indication using current CDC prescribing criteria versus transgender women-specific criteria developed by study investigators with community input. We identified factors associated with study-specific PrEP indication and factors associated with self-perceived low to no HIV risk among those who were PrEP-indicated. We also calculated descriptive statistics to depict the PrEP care continuum.

RESULTS

PrEP indication prevalence using transgender women-specific criteria was 47% (611), 155 more than who were identified using the CDC criteria. Eighty-three percent were aware of PrEP, among whom 38% had ever used PrEP. Among PrEP ever users, 63% were using PrEP at the time of the study. There were 66% of current PrEP users who reported 100% adherence within the previous 7 days. Among those who were PrEP-indicated, 13% were using and adherent to PrEP at the time of the study. More than half (55%) of PrEP-indicated participants had low or no self-perceived HIV risk.

CONCLUSIONS

These findings suggest that further guidance is needed for health care providers in prescribing PrEP to transgender women. Greater uptake and adherence are also needed for optimal effectiveness.

Perceived HIV Acquisition Risk and Low Uptake of PrEP Among a Cohort of Transgender Women With PrEP Indication in the Eastern and Southern United States

INTRODUCTION

Preexposure prophylaxis (PrEP) is effective in preventing HIV among adherent users. However, PrEP uptake among transgender women is low, and current prescribing guidelines from the Centers for Disease Control and Prevention (CDC) are not specific to transgender women. Self-perceived risk of HIV among those who are PrEP-indicated is not well understood.

METHODS

This cross-sectional analysis included 1293 transgender women screened at baseline from March 2018 to May 2020 for a multisite, prospective cohort study. We compared the prevalence of PrEP indication using current CDC prescribing criteria versus transgender women-specific criteria developed by study investigators with community input. We identified factors associated with study-specific PrEP indication and factors associated with self-perceived low to no HIV risk among those who were PrEP-indicated. We also calculated descriptive statistics to depict the PrEP care continuum.

RESULTS

PrEP indication prevalence using transgender women-specific criteria was 47% (611), 155 more than who were identified using the CDC criteria. Eighty-three percent were aware of PrEP, among whom 38% had ever used PrEP. Among PrEP ever users, 63% were using PrEP at the time of the study. There were 66% of current PrEP users who reported 100% adherence within the previous 7 days. Among those who were PrEP-indicated, 13% were using and adherent to PrEP at the time of the study. More than half (55%) of PrEP-indicated participants had low or no self-perceived HIV risk.

CONCLUSIONS

These findings suggest that further guidance is needed for health care providers in prescribing PrEP to transgender women. Greater uptake and adherence are also needed for optimal effectiveness.

Digital Epidemiologic Research on Multilevel Risks for HIV Acquisition and Other Health Outcomes Among Transgender Women in Eastern and Southern United States: Protocol for an Online Cohort

BACKGROUND

The HIV epidemic disproportionately impacts transgender women in the United States. Cohort studies identify unique risks for affected populations, but use of facility-based methods may bias findings towards individuals living in research catchment areas, more engaged in health services, or, in the case of transgender populations, those who are open about their transgender identity. Digital clinical trials and other online research methods are increasingly common, providing opportunity to reach those not commonly engaged in research. Simultaneously, there is a need to understand potential biases associated with digital research, how these methods perform, and whether they are accepted across populations.

OBJECTIVE

This study aims to assess the feasibility of developing and implementing an online cohort of transgender women to assess risks for HIV acquisition and other health experiences. Further, this study aims to evaluate how an online cohort compares to a site-based, technology-enhanced cohort for epidemiologic research. The overarching goal is to estimate incidence of HIV and other health outcomes among transgender women in eastern and southern United States.

METHODS

This substudy is part of a larger multisite prospective cohort (LITE) conducted among transgender women, which also includes a site-based, technology-enhanced cohort in 6 eastern and southern US cities. The online cohort was launched to enroll and follow participants across 72 cities in the same region and with similar demographic characteristics as the site-based cohort. Participants are followed for 24 months. Adult transgender women are recruited via convenience sampling (eg, peer referrals, social media, and dating apps). Participants reporting negative or unknown HIV status are enrolled in a baseline study visit, complete a sociobehavioral survey, and provide oral fluid specimens to test for HIV. Participants not living with HIV (lab-confirmed) at baseline are offered enrollment into the cohort; follow-up assessments occur every 6 months.

RESULTS

Enrollment into the online cohort launched in January 2019. Active recruitment stopped in May 2019, and enrollment officially closed in August 2020. A total of 580 participants enrolled into and are followed in the cohort. A recruitment-enrollment cascade was observed across screening, consent, and completion of study activities. Implementation experiences with HIV test kits highlight the need for heavy staff engagement to support participant engagement, visit completion, and retention, even with automated digital procedures.

CONCLUSIONS

This study is responsive to increasing research interest in digital observational and intervention research, particularly for populations who are most affected by the HIV epidemic and for those who may otherwise not participate in person. The progression across stages of the recruitment-enrollment cascade provides useful insight for implementation of cohort studies in the online environment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/29152.

American Cohort to Study HIV Acquisition Among Transgender Women in High-Risk Areas (The LITE Study): Protocol for a Multisite Prospective Cohort Study in the Eastern and Southern United States

BACKGROUND

In the United States, transgender women (TW) are disproportionately burdened by HIV infection. Cohort studies are needed to evaluate factors driving HIV acquisition among TW over time. These will require implementation strategies that are acceptable to the TW community and feasible to implement.

OBJECTIVE

This study aims to investigate the rate and correlates of HIV acquisition and other health outcomes among TW in eastern and southern United States.

METHODS

LITE is a multisite prospective cohort in 6 eastern and southern US cities, which will be followed across 24 months of technology-enhanced biobehavioral follow-up. Adult TW, regardless of HIV status, are recruited via convenience sampling (eg, peer referrals, social media, and dating apps). Participants are enrolled in a baseline study visit, complete a sociobehavioral survey, and test for HIV and sexually transmitted infections. Participants who are not living with HIV at baseline are offered enrollment into the cohort (N=1100); follow-up assessments occur quarterly.

RESULTS

Cohort assembly was informed by synchronous Web-based focus group discussions with TW (n=41) and by continuing engagement with community advisory board members from each site. Enrollment launched in March 2018. The study is underway in the Atlanta; Baltimore; Boston; Miami; New York City; and Washington, DC, metro areas. As of March 2019, 795 TW completed a baseline visit (mean age 35 years). The majority of the participants are racial/ethnic minorities, with 45% of the TW identifying as black and 28% of the TW identifying as Hispanic/Latinx. More than one-quarter (28%) of the TW are living with HIV infection (laboratory-confirmed). Online recruitment methods support engagement with TW, although peer referral and referral through trusted health facilities and organizations remain most effective.

CONCLUSIONS

This study is responsive to increasing research interest in technology-enhanced methods for cohort research, particularly for hard-to-reach populations. Importantly, the diversity of literacy, technology use, and overall socioeconomic situations in this sample of TW highlights the need to leverage technology to permit a flexible, adaptive methodology that enhances engagement of potential participants living in marginalized contexts while still ensuring rigorous and sound study design.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/14704.

Implementation of an Immediate HIV Treatment Initiation Program in a Public/Academic Medical Center in the U.S. South: The Miami Test and Treat Rapid Response Program

Test and Rapid Response Treatment (TRRT) linkage programs have demonstrated improved HIV suppression rates. This paper describes the design and implementation of the Miami TRRT initiative and its clinical impact. Assisted by a dedicated care navigator, patients receiving a reactive HIV rapid test at the Florida Department of Health STD Clinic were offered same-day HIV care at the University of Miami/Jackson Memorial Medical Center Adult HIV Outpatient Clinic. Patient retention and labs were tracked for 12 months. Of the 2337 individuals tested, 46 had a reactive HIV test; 41 (89%) consented to participate. For the 36 patients in continued care for a year, 33 (91.7%) achieved virological suppression (< 200 copies/mL) within 70 days of their reactive HIV rapid test; at 12 months, 35 (97.2%) remained suppressed, and mean CD4 T cell counts increased from 452 ± 266 to 597 ± 322 cells/mm³. The Miami TRRT initiative demonstrated that immediate linkage to care is feasible and improves retention and suppression in a public/academic medical center in the U.S. South.

Psychological stress and short-term hospitalisations or death in patients with heart failure

OBJECTIVE

Standard predictors do not fully explain variations in the frequency and timing of heart failure (HF) adverse events (AEs). Psychological stress can trigger acute cardiovascular (CV) events, but it is not known whether stress can precipitate AEs in patients with HF. We investigated prospective associations of psychological stress with AEs in patients with HF.

METHODS

144 patients with HF (77% male; 57.5±11.5, range 23-87 years, left ventricular ejection fraction ≤40%) were longitudinally evaluated for psychological stress (Perceived Stress Scale) and AEs (CV hospitalisations/death) at 2-week intervals for 3 months and at 9-month follow-up.

RESULTS

42 patients (29.2%) had at least one CV hospitalisation and nine (6.3%) died. Patients reporting high average perceived stress across study measurements had a higher likelihood of AEs during the study period compared with those with lower stress (odds ratio=1.10, 95% confidence interval=1.04 to 1.17). In contrast to average levels, increases in stress did not predict AEs (p=0.96). Perceived stress was elevated after a CV hospitalisation (B=2.70, standard error (SE)=0.93, p=0.004) suggesting that CV hospitalisations increase stress. Subsequent analysis indicated that 24 of 38 (63%) patients showed a stress increase following hospitalisation. However, a prospective association between stress and AEs was present when accounting for prior hospitalisations (B=2.43, SE=1.23, p=0.05).

CONCLUSIONS

Sustained levels of perceived stress are associated with increased risk of AEs, and increased distress following hospitalisation occurs in many, but not all, patients with HF. Patients with chronically high stress may be an important target group for HF interventions aimed at reducing hospitalisations.

Decreased reaction time variability is associated with greater cardiovascular responses to acute stress

Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses.

High Concordance Between Mental Stress-Induced and Adenosine-Induced Myocardial Ischemia Assessed Using SPECT in Heart Failure Patients: Hemodynamic and Biomarker Correlates

Mental stress can trigger myocardial ischemia, but the prevalence of mental stress-induced ischemia in congestive heart failure (CHF) patients is unknown. We characterized mental stress-induced and adenosine-induced changes in myocardial perfusion and neurohormonal activation in CHF patients with reduced left-ventricular function using SPECT to precisely quantify segment-level myocardial perfusion.

METHODS

Thirty-four coronary artery disease patients (mean age±SD, 62±10 y) with CHF longer than 3 mo and ejection fraction less than 40% underwent both adenosine and mental stress myocardial perfusion SPECT on consecutive days. Mental stress consisted of anger recall (anger-provoking speech) followed by subtraction of serial sevens. The presence and extent of myocardial ischemia was quantified using the conventional 17-segment model.

RESULTS

Sixty-eight percent of patients had 1 ischemic segment or more during mental stress and 81% during adenosine. On segment-by-segment analysis, perfusion with mental stress and adenosine were highly correlated. No significant differences were found between any 2 time points for B-type natriuretic peptide, tumor necrosis factor-α, IL-1b, troponin, vascular endothelin growth factor, IL-17a, matrix metallopeptidase-9, or C-reactive protein. However, endothelin-1 and IL-6 increased, and IL-10 decreased, between the stressor and 30 min after stress. Left-ventricular end diastolic dimension was 179±65 mL at rest and increased to 217±71 after mental stress and 229±86 after adenosine (P<0.01 for both). Resting end systolic volume was 129±60 mL at rest and increased to 158±66 after mental stress (P<0.05) and 171±87 after adenosine (P<0.07), with no significant differences between adenosine and mental stress. Ejection fraction was 30±12 at baseline, 29±11 with mental stress, and 28±10 with adenosine (P=not significant).

CONCLUSION

There was high concordance between ischemic perfusion defects induced by adenosine and mental stress, suggesting that mental stress is equivalent to pharmacologic stress in eliciting clinically significant myocardial perfusion defects in CHF patients. Cardiac dilatation suggests clinically important changes with both conditions. Psychosocial stressors during daily life may contribute to the ischemic burden of CHF patients with coronary artery disease.

Positive emotional style and subjective, cardiovascular and cortisol responses to acute laboratory stress

The relationships between positive emotional style and acute salivary cortisol and cardiovascular responses to laboratory stress tasks were examined in 40 young women (mean age=28.8 years). Positive emotional style (PES) was measured by aggregating daily positive mood rating scales over one week. Negative affect was assessed with the short form Profile of Mood States. Salivary cortisol was measured in response to two behavioural tasks, a 5 min speech task and a 5 min mirror tracing task. Blood pressure (BP) and heart rate responses were monitored using a Finometer during baseline, tasks and recovery. Higher PES was associated with more complete diastolic BP recovery (p=0.027) and lower acute cortisol response to stress (p=0.018), after adjusting for baseline measures, age, BMI and negative affect. Individuals with higher PES reported lower subjective tension during the tasks and perceived the tasks as more controllable. There were no differences in ratings of task involvement or in objective measures of task performance. A retrospective measure of positive affect (POMS vigour) was associated with diastolic BP recovery but not cortisol responses or subjective tension. The findings suggest that positive affective traits, assessed using repeated assessments of daily mood, are related to adaptive recovery from acute psychological stress. Our results reinforce evidence linking positive affect with adaptive diastolic BP recovery, while extending the results to cortisol. Investigations into the biological correlates of affective traits should consider utilising repeated measures of experienced affect.

The effects of exercise withdrawal on mood and inflammatory cytokine responses in humans

Mechanisms underlying the relationship between exercise and mood are not well understood. This study sought to investigate the role of pro- and anti-inflammatory cytokines and autonomic balance in determining the impact of exercise withdrawal on negative mood. Healthy men and women who regularly exercised (N = 26, mean age = 25.5 years, SD = 4.5 years) were randomised to exercise withdrawal or exercise maintenance for 2 weeks. Protocol adherence was monitored using accelerometers. Inflammatory markers from plasma (interleukin-6, IL-6; tumour necrosis factor-alpha; interleukin-10; and interleukin-1 receptor antagonist), heart-rate variability (HRV) and measures of mood (General Health Questionnaire-28 (GHQ) and the Profile of Mood States (POMS)) were assessed at study entry and at 2-week follow-up. Exercise withdrawal resulted in significant increases in negative mood over time on both the GHQ (p = 0.028) and the POMS (p = 0.005). Following the intervention, IL-6 concentration was lower in the exercise withdrawal than exercise maintenance condition (p = 0.05). No intervention effects were observed for other cytokines or HRV. The mood changes were significantly related to changes in IL-6 concentration (β = - 0.50, p = 0.011), indicating that reduction in IL-6 was related to increased negative mood. Our results are consistent with positive effects of exercise on mental health, but further research on inflammatory pathways is warranted.

The SF-36 component summary scales and the daytime diurnal cortisol profile

PURPOSE

Higher daytime cortisol output has been associated with higher levels of perceived stress and worse mental and physical health outcomes. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation, such as elevated secretion of daytime cortisol, occurs in many mental and physical illnesses. However, the nature of the association between functional health status and daytime cortisol production has not been established.

METHODS

Healthy adult volunteers (n=68, 45 females) provided saliva samples 3, 6, 9 and 12 h after waking, for two consecutive days, in everyday settings. Bivariate correlations between log salivary cortisol concentrations were calculated, and the SF-36 component summary scores were calculated. Latent growth curve modeling was used to model the daytime profile and adjust for covariates (age, sex and waking time).

RESULTS

Higher PCS scores were not associated with cortisol three hours after waking (cortisol intercept), or the diurnal decline (cortisol slope). Higher MCS scores were correlated with faster cortisol decline across the day (r=-.31, P<.01) but not with cortisol intercepts. In a latent growth curve model adjusting for age, sex and waking time, the association was no longer statistically significant.

CONCLUSIONS

Large scale epidemiological studies involving salivary cortisol would benefit from measuring SF-36 component summary scores. Cortisol intercepts and slopes may be differentially related to the PCS and MCS, although greater statistical power is needed to test this hypothesis more fully. Associations between daytime cortisol and the PCS or MCS could reflect the regulatory competence of bodily systems, common causes or unmeasured confounding factors.

Dispositional optimism and stress-induced changes in immunity and negative mood

Evidence suggests that optimism may be protective for health during times of heightened stress, yet the mechanisms involved remain unclear. In a double-blind placebo-controlled study, we recently showed that acute psychological stress and an immune stimulus (Typhim-Vi typhoid vaccine) synergistically increased serum levels of interleukin-6 (IL-6) and negative mood in 59 healthy men. Here we carried out further analysis of this sample to investigate the relationship between dispositional optimism and stress-induced changes in immunity and mood. Volunteers were randomly assigned to one of four experimental conditions in which they received either typhoid vaccine or saline placebo, and then rested or completed two mental tasks. In the stress condition, optimism was inversely related to IL-6 responses, independent of age, BMI, trait CES-D depression and baseline IL-6. This relationship was present across both stress groups (combining vaccine and placebo) and was not present in the vaccine/stress group alone, suggesting that optimism protects against the inflammatory effects of stress rather than vaccine per se. Typhoid vaccine induced a significant increase in participants' circulating anti-Vi antibody levels. Stress had no effect on antibody responses overall. However, in the vaccine/stress group, there was a strong positive association between optimism and antibody responses, indicating that stress accentuated the antibody response to vaccine in optimists. Across the complete sample, more optimistic individuals had smaller increases in negative mood and less reduction in mental vigour. Together these findings suggest that optimism may promote health, by counteracting stress-induced increases in inflammation and boosting the adjuvant effects of acute stress.

Circulating leptin and stress-induced cardiovascular activity in humans

Obesity is associated with an elevated risk of hypertension and cardiovascular disease. The adipocyte hormone leptin, which stimulates energy expenditure in animals by activating the sympathetic nervous system (SNS), is believed to play a role in this association. However, evidence in humans remains sparse. We investigated the relationship between circulating leptin and cardiovascular and inflammatory responses to acute psychological stress in humans. Participants were 32 men and 62 women aged 18-25 years. Cardiovascular activity was assessed using impedance cardiography at baseline, during acute laboratory stress, and during a 45-min recovery period. Plasma cytokines were measured in blood drawn at baseline and 45-min poststress. In women only, baseline plasma leptin was significantly associated with stress-induced changes in heart rate (beta = 0.53, P = 0.006), heart rate variability (HRV) (beta = -0.44, P = 0.015), and cardiac preejection period (PEP) (beta = -0.51, P = 0.004), independent of age, adiposity, and smoking. Women's plasma leptin levels also correlated with stress-induced elevations in the proinflammatory cytokine interleukin-6 (IL-6) (beta = 0.35, P = 0.042). Circulating leptin is an independent predictor of sympathetic cardiovascular activity, parasympathetic withdrawal, and inflammatory responses to stress in women. Because cardiovascular and inflammatory stress responses are predictive of future cardiovascular disease, leptin may be a mechanism mediating the adverse effects of stress and obesity on women's cardiovascular health.

Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery

BACKGROUND

Peripheral arterial disease (PAD) may cause occlusions (blockages) in the main arteries of lower limbs. One treatment option is bypass surgery using autologous (the patient's own tissue) vein graft or artificial graft. A number of factors influence occlusion rates, including the material used. To prevent graft occlusion patients are usually treated with antiplatelet, antithrombotic drugs, or a combination of both.

OBJECTIVES

To evaluate whether antiplatelet treatment in patients with symptomatic PAD undergoing infrainguinal bypass surgery improves graft patency, limb salvage and survival.

SEARCH STRATEGY

The authors searched the Cochrane Peripheral Vascular Diseases Group Specialised Register (January 2008) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4). Additional trials were sought through reference lists of papers and proceedings from the vascular surgical society meetings.

SELECTION CRITERIA

For this update the methodological quality of each original trial was assessed independently by review authors (JB, HM, AW) with emphasis on concealment of allocation.

DATA COLLECTION AND ANALYSIS

Details of the selected studies were extracted independently by JB and HM for the update. The treatment and control groups were compared for important prognostic factors and differences described. If any data were unavailable, further information was sought from authors. Data were synthesised by comparing group results. Unit of analysis issues were addressed by subgroup analysis.

MAIN RESULTS

The administration of a variety of platelet inhibitors resulted in improved venous and artificial graft patency when compared to no treatment. However, analysing patients for graft-type indicated that those patients receiving a prosthetic graft were more likely to benefit from administration of platelet inhibitors than patients treated with venous grafts.

AUTHORS' CONCLUSIONS

Antiplatelet therapy with aspirin had a slight beneficial effect on the patency of peripheral bypass grafts but seemed to have an inferior effect on venous graft patency compared with artificial grafts. The effect of aspirin on cardiovascular outcomes and survival was small and not statistically significant. This might be due to the fact that the majority of patients receiving a peripheral graft have an advanced stage of PAD with critical ischaemia. They are usually seriously ill as a result of cardiovascular disease and have high mortality rates, of 20% per year. Additionally, the number of patients included in this analysis might be too small to reach a statistically significant effect for mortality and cardiovascular morbidity.