Sex Differences in Vascular Response to Mental Stress and Adverse Cardiovascular Events Among Patients With Ischemic Heart Disease.

BACKGROUND: Microvascular measures of vascular dysfunction during acute mental stress may be important determinants of major adverse cardiovascular events (MACE), especially among younger and middle-aged women survivors of an acute myocardial infarction. METHODS: In the MIMS2 study (Myocardial Infarction and Mental Stress 2), individuals who had been hospitalized for a myocardial infarction in the past 8 months were prospectively followed for 5 years. MACE was defined as a composite index of cardiovascular death and first/recurring events for nonfatal myocardial infarction and hospitalizations for heart failure. Reactive hyperemia index and flow-mediated dilation were used to measure microvascular and endothelial function, respectively, before and 30 minutes after a public-speaking mental stress task. Survival models for recurrent events were used to examine the association between vascular response to stress (difference between poststress and resting values) and MACE. Reactive hyperemia index and flow-mediated dilation were standardized in analyses. RESULTS: Of 263 patients (the mean age was 51 years; range, 25-61), 48% were women, and 65% were Black. During a median follow-up of 4.3 years, 64 patients had 141 adverse cardiovascular events (first and repeated). Worse microvascular response to stress (for each SD decrease in the reactive hyperemia index) was associated with 50% greater risk of MACE (hazard ratio, 1.50 [95% CI, 1.05-2.13]; P=0.03) among women only (sex interaction: P=0.03). Worse transient endothelial dysfunction in response to stress (for each SD decrease in flow-mediated dilation) was associated with a 35% greater risk of MACE (hazard ratio, 1.35 [95% CI, 1.07-1.71]; P=0.01), and the association was similar in women and men. CONCLUSIONS: Peripheral microvascular dysfunction with mental stress was associated with adverse events among women but not men. In contrast, endothelial dysfunction was similarly related to MACE among both men and women. These results suggest a female-specific mechanism linking psychological stress to adverse outcomes.

Racial Differences in Mental Stress-Induced Transient Endothelial Dysfunction and Its Association With Cardiovascular Outcomes.

OBJECTIVE: This study aimed to investigate differences in transient endothelial dysfunction (TED) with mental stress in Black and non-Black individuals with coronary heart disease (CHD), and their potential impact on cardiovascular outcomes. METHODS: We examined 812 patients with stable CHD between June 2011 and March 2016 and followed through February 2020 at a university-affiliated hospital network. Flow-mediated vasodilation (FMD) was assessed before and 30 minutes after mental stress. TED was defined as a lower poststress FMD than prestress FMD. We compared prestress FMD, post-stress FMD, and TED between Black and non-Black participants. In both groups, we examined the association of TED with an adjudicated composite end point of cardiovascular death or nonfatal myocardial infarction (first and recurring events) after adjusting for demographic, clinical, and socioeconomic factors. RESULTS: Prestress FMD was lower in Black than non-Black participants (3.7 [2.8] versus 4.9 [3.8], p < .001) and significantly declined with mental stress in both groups. TED occurred more often in Black (76%) than non-Black patients (67%; multivariable-adjusted odds ratio = 1.6, 95% confidence interval = 1.5-1.7). Over a median (interquartile range) follow-up period of 75 (65-82) months, 142 (18%) patients experienced either cardiovascular death or nonfatal myocardial infarction. Black participants had a 41.9% higher risk of the study outcome than non-Black participants (95% confidence interval = 1.01-1.95). TED with mental stress explained 69% of this excess risk. CONCLUSIONS: Among CHD patients, Black individuals are more likely than non-Black individuals to develop endothelial dysfunction with mental stress, which in turn explains a substantial portion of their excess risk of adverse events.

Quantitation of diffuse myocardial ischemia with mental stress and its association with cardiovascular events in individuals with recent myocardial infarction.

Microcirculatory dysfunction during psychological stress may lead to diffuse myocardial ischemia. We developed a novel quantification method for diffuse ischemia during mental stress (dMSI) and examined its relationship with outcomes after a myocardial infarction (MI). We studied 300 patients ≤ 61 years of age (50% women) with a recent MI. Patients underwent myocardial perfusion imaging with mental stress and were followed for 5 years. dMSI was quantified from cumulative count distributions of rest and stress perfusion. Focal ischemia was defined in a conventional fashion. The main outcome was a composite outcome of recurrent MI, heart failure hospitalizations, and cardiovascular death. A dMSI increment of 1 standard deviation was associated with a 40% higher risk for adverse events (HR 1.4, 95% CI 1.2-1.5). Results were similar after adjustment for viability, demographic and clinical factors and focal ischemia. In sex-specific analysis, higher levels of dMSI (per standard deviation increment) were associated with 53% higher risk of adverse events in women (HR 1.5, 95% CI 1.2-2.0) but not in men (HR 0.9, 95% CI 0.5-1.4), P 0.001. A novel index of diffuse ischemia with mental stress was associated with recurrent events in women but not in men after MI.

Early life stress and autonomic response to acute mental stress in individuals with coronary heart disease.

Early life stress (ELS) has been associated with an increased risk of cardiovascular disease. We examined whether ELS was associated with autonomic function and stress reactivity among individuals with coronary heart disease (CHD). We included patients with stable CHD from two parallel studies, the Mental Stress Ischemia Prognosis Study (MIPS) and the Myocardial Infarction and Mental Stress Study 2 (MIMS2), and assessed ELS using the Early Trauma Inventory-Self-Report-Short Form. Participants underwent a laboratory-based mental stress task while undergoing ambulatory electrocardiographic monitoring. We used multivariate linear regression models to estimate the associations between ELS and heart rate variability (HRV; low frequency [LF], high frequency [HF], and LF and HF [LH] ratio). The analytic sample included 405 MIPS and 284 MIMS2 participants. Most participants endorsed at least one experience of ELS (92.2%). Although we did not observe associations between ELS and HRV outcomes in the overall sample, ELS was associated with lower LH ratio HRV during recovery in the posttraumatic stress disorder (PTSD) subgroup, ELS x PTSD interaction, p = .041. In the MIMS2 subgroup, ELS was associated with lower resting period LF HRV, B ̂ $ \widehat{B} $  = -0.16 ln ms2 ; 95% CI [-0.31, -0.02]. Exposure to physical trauma was associated with decreased HF HRV overall reactivity only among participants with high to moderate depressive symptoms, B ̂ $ \widehat{B} $  = -0.52 ln ms2 vs. B ̂ $ \widehat{B} $  = 0.01 ln ms2 , p = .013. Overall, heterogeneous associations between ELS and HRV emerged, suggesting the need for additional research regarding longer-term ambulatory HRV.

Everyday Discrimination and Mental Stress-Induced Myocardial Ischemia.

OBJECTIVE: Mental stress-induced myocardial ischemia (MSIMI), a transient myocardial ischemic response to mental stress, is associated with poorer outcomes among patients with coronary heart disease and is more likely to occur among women. However, predictors of MSIMI are not well explored. The current study investigated the association between experiences of everyday discrimination and MSIMI among patients with recent myocardial ischemia and contrasted the results with conventional stress-induced myocardial ischemia (CSIMI). We examined sex differences in associations. METHODS: We studied 295 post-MI patients (145 women, 150 men). Provocation of myocardial ischemia with mental stress (speech task) and conventional stress (exercise or pharmacologic) was assessed by myocardial perfusion imaging. Frequency of exposure to everyday discrimination was assessed via questionnaire using the Everyday Discrimination Scale (EDS). RESULTS: The mean age was 51 years in both women and men, and the EDS score ranged from 10 to 38 (mean [standard deviation] = 17 [6] years). After multivariable analysis, each standard deviation increase in the EDS score (more frequent exposure) was associated with an increased odds of MSIMI (odds ratio [OR] = 1.57 [1.10-2.23]). The EDS score was not associated with CSIMI (OR = 0.86 [0.64-1.17]). Women demonstrated a twofold increase (OR = 1.96 [1.13-3.38], p = .02) in the adjusted odds of MSIMI, with each standard deviation increase in the EDS score compared with a 1.4-fold increase (OR = 1.40 [0.80-2.44], p = .24) among men; however, interaction was not statistically significant. CONCLUSIONS: Among post-MI patients, everyday discrimination was positively associated with occurrence of MSIMI, but not with CSIMI; associations were more pronounced among women.

A modified physiological strain index for workplace-based assessment of heat strain experienced by agricultural workers.

BACKGROUND: As global temperatures rise, increasing numbers of individuals will work in hot environments. Interventions to protect their health are critical, as are reliable methods to measure the physiological strain experienced from heat exposure. The physiological strain index (PSI) is a measure of heat strain that relies on heart rate and core temperature but is challenging to calculate in a real-world occupational setting. METHODS: We modified the PSI for use in field settings where resting temperature and heart rate are not available and used the modified physiological strain index (mPSI) to describe risk factors for high heat strain (mPSI ≥ 7) experienced by agricultural workers in Florida during the summers of 2015 through 2017. mPSI was calculated for 221 workers, yielding 465 days of data. RESULTS: A higher heat index (ß = 0.185; 95% CI: 0.064, 0.307) and higher levels of physical activity at work (0.033; 95% CI: 0.017, 0.050) were associated with a higher maximum mPSI. More years worked in US agriculture (-0.041; 95% CI: -0.061, -0.020) were protective against a higher maximum mPSI. Out of 23 workdays that a participant experienced a maximum mPSI ≥ 7, 22 were also classified as strained by at least one other measure of high heat strain (core temperature [Tc] >38.5°C, sustained heart rate >(180 - age), and mean heart rate > 115 bpm). CONCLUSIONS: This study provides critical information on risk factors for elevated heat strain for agricultural workers and suggests a practical approach for using PSI in field-based settings.

Behaviors, movements, and transmission of droplet-mediated respiratory diseases during transcontinental airline flights.

With over 3 billion airline passengers annually, the inflight transmission of infectious diseases is an important global health concern. Over a dozen cases of inflight transmission of serious infections have been documented, and air travel can serve as a conduit for the rapid spread of newly emerging infections and pandemics. Despite sensational media stories and anecdotes, the risks of transmission of respiratory viruses in an airplane cabin are unknown. Movements of passengers and crew may facilitate disease transmission. On 10 transcontinental US flights, we chronicled behaviors and movements of individuals in the economy cabin on single-aisle aircraft. We simulated transmission during flight based on these data. Our results indicate there is low probability of direct transmission to passengers not seated in close proximity to an infectious passenger. This data-driven, dynamic network transmission model of droplet-mediated respiratory disease is unique. To measure the true pathogen burden, our team collected 229 environmental samples during the flights. Although eight flights were during Influenza season, all qPCR assays for 18 common respiratory viruses were negative.

Association of Mental Stress-Induced Myocardial Ischemia With Cardiovascular Events in Patients With Coronary Heart Disease.

Importance: Mental stress-induced myocardial ischemia is a recognized phenomenon in patients with coronary heart disease (CHD), but its clinical significance in the contemporary clinical era has not been investigated. Objective: To compare the association of mental stress-induced or conventional stress-induced ischemia with adverse cardiovascular events in patients with CHD. Design, Setting, and Participants: Pooled analysis of 2 prospective cohort studies of patients with stable CHD from a university-based hospital network in Atlanta, Georgia: the Mental Stress Ischemia Prognosis Study (MIPS) and the Myocardial Infarction and Mental Stress Study 2 (MIMS2). Participants were enrolled between June 2011 and March 2016 (last follow-up, February 2020). Exposures: Provocation of myocardial ischemia with a standardized mental stress test (public speaking task) and with a conventional (exercise or pharmacological) stress test, using single-photon emission computed tomography. Main Outcomes and Measures: The primary outcome was a composite of cardiovascular death or first or recurrent nonfatal myocardial infarction. The secondary end point additionally included hospitalizations for heart failure. Results: Of the 918 patients in the total sample pool (mean age, 60 years; 34% women), 618 participated in MIPS and 300 in MIMS2. Of those, 147 patients (16%) had mental stress-induced ischemia, 281 (31%) conventional stress ischemia, and 96 (10%) had both. Over a 5-year median follow-up, the primary end point occurred in 156 participants. The pooled event rate was 6.9 per 100 patient-years among patients with and 2.6 per 100 patient-years among patients without mental stress-induced ischemia. The multivariable adjusted hazard ratio (HR) for patients with vs those without mental stress-induced ischemia was 2.5 (95% CI, 1.8-3.5). Compared with patients with no ischemia (event rate, 2.3 per 100 patient-years), patients with mental stress-induced ischemia alone had a significantly increased risk (event rate, 4.8 per 100 patient-years; HR, 2.0; 95% CI, 1.1-3.7) as did patients with both mental stress ischemia and conventional stress ischemia (event rate, 8.1 per 100 patient-years; HR, 3.8; 95% CI, 2.6-5.6). Patients with conventional stress ischemia alone did not have a significantly increased risk (event rate, 3.1 per 100 patient-years; HR, 1.4; 95% CI, 0.9-2.1). Patients with both mental stress ischemia and conventional stress ischemia had an elevated risk compared with patients with conventional stress ischemia alone (HR, 2.7; 95% CI, 1.7-4.3). The secondary end point occurred in 319 participants. The event rate was 12.6 per 100 patient-years for patients with and 5.6 per 100 patient-years for patients without mental stress-induced ischemia (adjusted HR, 2.0; 95% CI, 1.5-2.5). Conclusions and Relevance: Among patients with stable coronary heart disease, the presence of mental stress-induced ischemia, compared with no mental stress-induced ischemia, was significantly associated with an increased risk of cardiovascular death or nonfatal myocardial infarction. Although these findings may provide insights into mechanisms of myocardial ischemia, further research is needed to assess whether testing for mental stress-induced ischemia has clinical value.

Race and Gender Differences in the Association Between Experiences of Everyday Discrimination and Arterial Stiffness Among Patients With Coronary Heart Disease.

BACKGROUND: Self-reported experiences of discrimination have been linked to indices of cardiovascular disease. However, most studies have focused on healthy populations. Thus, we examined the association between experiences of everyday discrimination and arterial stiffness among patients with a history of myocardial infarction (MI). PURPOSE: We hypothesized that higher reports of discrimination would be associated with greater arterial stiffness and that associations would be more pronounced among Black women, in particular, relative to other race-gender groups, using an "intersectionality" perspective. METHODS: Data were from 313 participants (49.2% female, mean age: 50.8 years) who were 6 months post-MI in the Myocardial Infarction and Mental Stress 2 study. Data were collected via self-reported questionnaires, medical chart review, and a clinic visit during which arterial stiffness was measured noninvasively using pulse wave velocity. RESULTS: Reports of discrimination were highest in Black men and women and arterial stiffness was greatest in Black and White women. After adjustment for demographics and relevant clinical variables, discrimination was not associated with arterial stiffness in the overall study sample. However, discrimination was associated with increased arterial stiffness among Black women but not White women, White men, or Black men. CONCLUSIONS: Despite no apparent association between discrimination and arterial stiffness in the overall study sample, further stratification revealed an association among Black women but not other race-gender groups. These data not only support the utility of an intersectionality lens but also suggest the importance of implementing psychosocial interventions and coping strategies focused on discrimination into the care of clinically ill Black women.

Mental Stress-Induced-Myocardial Ischemia in Young Patients With Recent Myocardial Infarction: Sex Differences and Mechanisms.

BACKGROUND: Mental stress-induced myocardial ischemia (MSIMI) is frequent in patients with coronary artery disease and is associated with worse prognosis. Young women with a previous myocardial infarction (MI), a group with unexplained higher mortality than men of comparable age, have shown elevated rates of MSIMI, but the mechanisms are unknown. METHODS: We studied 306 patients (150 women and 156 men) ≤61 years of age who were hospitalized for MI in the previous 8 months and 112 community controls (58 women and 54 men) frequency matched for sex and age to the patients with MI. Endothelium-dependent flow-mediated dilation and microvascular reactivity (reactive hyperemia index) were measured at rest and 30 minutes after mental stress. The digital vasomotor response to mental stress was assessed using peripheral arterial tonometry. Patients received 99mTc-sestamibi myocardial perfusion imaging at rest, with mental (speech task) and conventional (exercise/pharmacological) stress. RESULTS: The mean age of the sample was 50 years (range, 22-61). In the MI group but not among controls, women had a more adverse socioeconomic and psychosocial profile than men. There were no sex differences in cardiovascular risk factors, and among patients with MI, clinical severity tended to be lower in women. Women in both groups showed a higher peripheral arterial tonometry ratio during mental stress but a lower reactive hyperemia index after mental stress, indicating enhanced microvascular dysfunction after stress. There were no sex differences in flow-mediated dilation changes with mental stress. The rate of MSIMI was twice as high in women as in men (22% versus 11%, P=0.009), and ischemia with conventional stress was similarly elevated (31% versus 16%, P=0.002). Psychosocial and clinical risk factors did not explain sex differences in inducible ischemia. Although vascular responses to mental stress (peripheral arterial tonometry ratio and reactive hyperemia index) also did not explain sex differences in MSIMI, they were predictive of MSIMI in women only. CONCLUSIONS: Young women after MI have a 2-fold likelihood of developing MSIMI compared with men and a similar increase in conventional stress ischemia. Microvascular dysfunction and peripheral vasoconstriction with mental stress are implicated in MSIMI among women but not among men, perhaps reflecting women's proclivity toward ischemia because of microcirculatory abnormalities.

Sex-Specific Association Between Coronary Artery Disease Severity and Myocardial Ischemia Induced by Mental Stress.

OBJECTIVE: It is unclear whether mental stress-induced myocardial ischemia (MSIMI) is related to obstructive coronary artery disease (CAD). We examined this question and contrasted results with ischemia induced by conventional stress testing (CSIMI). Because women are more susceptible to ischemia without coronary obstruction than men, we examined sex differences. METHODS: We studied 276 patients 61 years and younger with recent myocardial infarction. CAD severity was quantified using the log-transformed Gensini Score (lnGS) and the Sullivan Stenosis Score. Patients underwent myocardial perfusion imaging with mental stress (public speaking) and conventional (exercise or pharmacological) stress testing. MSIMI and CSIMI were defined as a new or worsening perfusion defect. RESULTS: The prevalence of MSIMI was 15% in men and 20% in women. The median GS for patients with MSIMI was 65.0 in men and 28.5 in women. In logistic regression models adjusted for demographic and cardiovascular risk factors, CAD severity was associated with CSIMI in the full sample (odds ratio [OR] = 1.49, 95% [CI], 1.14-1.95, per 1-unit increase in lnGS), with no significant difference by sex. Although CAD severity was not associated with MSIMI in the entire sample, results differed by sex. CAD severity was associated with MSIMI among men (OR = 1.95, 95% CI, 1.13-3.36, per 1-unit increase in lnGS), but not among women (OR = 1.02, 95% CI, 0.74-1.42, p = .042 for interaction). Analysis using Sullivan Stenosis Score yielded similar results. CONCLUSIONS: Findings suggest that CAD severity is related to MSIMI in men but not women. MSIMI in women may therefore be driven by alternative mechanisms such as coronary microvascular disease.

Posttraumatic stress disorder is associated with enhanced interleukin-6 response to mental stress in subjects with a recent myocardial infarction.

BACKGROUND: Posttraumatic Stress Disorder (PTSD) is prevalent among patients who survived an acute coronary syndrome, and is associated with adverse outcomes, but the mechanisms underlying these associations are unclear. Individuals with PTSD have enhanced sensitivity of the noradrenergic system to stress which may lead to immune activation. We hypothesized that survivors of a myocardial infarction (MI) who have PTSD would show an enhanced inflammatory response to acute psychological stress compared to those without PTSD. METHODS: Individuals with a verified history of MI within 8 months and a clinical diagnosis of current PTSD underwent a mental stress speech task. Inflammatory biomarkers including interleukin-6 (IL-6), high-sensitivity C reactive protein (HsCRP), matrix metallopeptidase 9 (MMP-9), intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1 and monocyte chemoattractant protein (MCP)-1 were measured at rest and 90 min after mental stress. RESULTS: Among 271 patients in the study (mean age 51 ±â€¯7 years, 50% female, 60% African-American), the prevalence of PTSD was 12%. Mental stress resulted in a significant increase in IL-6, but the increase was more marked in patients with PTSD (126% increase) than those without (63% increase) (p = 0.001). MCP-1 showed a modest increase with stress which was similar in patients with PTSD (9% increase) and without PTSD (6% increase) (p = 0.35). CRP did not increase with stress in either group. CONCLUSION: MI patients with current PTSD exhibit enhanced IL-6 response to psychosocial stress, suggesting a mechanistic link between PTSD and adverse cardiovascular outcomes as well as other diseases associated with inflammation.

Physical activity and work activities in Florida agricultural workers.

BACKGROUND: Laboring in hot and humid conditions is a risk factor for heat-related illnesses. Little is known about the amount of physical activity performed in the field setting by agricultural workers, a population that is among those at highest risk for heat-related mortality in the United States. METHODS: We measured accelerometer-based physical activity and work activities performed in 244 Florida agricultural workers, 18 to 54 years of age, employed in the fernery, nursery, and crop operations during the summer work seasons of 2015-2017. Environmental temperature data during the participant's workdays were collected from the Florida Automated Weather Network and used to calculate wet bulb globe temperature (WBGT). Generalized linear mixed model regression was used to examine the association between WBGT on physical activity, stratified by the agricultural sector. RESULTS: Fernery workers had the highest overall volume of physical activity, spending nearly 4 hours in moderate to vigorous activity per workday. Activity over the course of the workday also differed by the agricultural sector. A reduction on average physical activity with increasing environmental temperature was observed only among crop workers. CONCLUSIONS: The quantity and patterns of physical activity varied by the agricultural sector, sex, and age, indicating that interventions that aim to reduce heat-related morbidity and mortality should be tailored to specific subpopulations. Some workers did not reduce overall physical activity under dangerously hot environmental conditions, which has implications for policies protecting worker health. Future research is needed to determine how physical activity and climatic conditions impact the development of heat-related disorders in this population.

Classification of Heat-Related Illness Symptoms Among Florida Farmworkers.

BACKGROUND: Farmworkers working in hot and humid environments have an increased risk for heat-related illness (HRI) if their thermoregulatory capabilities are overwhelmed. The manifestation of heat-related symptoms can escalate into life-threatening events. Increasing ambient air temperatures resulting from climate change will only exacerbate HRI in vulnerable populations. We characterize HRI symptoms experienced by farmworkers in three Florida communities. METHODS: A total of 198 farmworkers enrolled in 2015-2016 were asked to recall if they experienced seven HRI symptoms during the previous work week. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between selected sociodemographic characteristics and reporting three or more symptoms. Latent class analysis was used to identify classes of symptoms representing the HRI severity range. We examined sociodemographic characteristics of the farmworkers across the latent classes. RESULTS: The mean age (±SD) of farmworkers was 38.0 (±8) years; the majority were female (60%) and Hispanic (86%). Most frequently reported symptoms were heavy sweating (66%), headache (58%), dizziness (32%), and muscle cramps (30%). Females had three times the odds of experiencing three or more symptoms (OR = 2.86, 95% CI 1.18-6.89). Symptoms fell into three latent classes, which included mild (heavy sweating; class probability = 54%), moderate (heavy sweating, headache, nausea, and dizziness; class probability = 24%), and severe (heavy sweating, headache, nausea, dizziness, muscle cramps; class probability = 22%). CONCLUSIONS: Farmworkers reported a high burden of HRI symptoms that appear to cluster in physiologic patterns. Unrecognized accumulation of symptoms can escalate into life-threatening situations if untreated. Our research can inform interventions to promote early recognition of HRI, on-site care, and appropriate occupational health policy. Administrative or engineering workplace controls may also reduce the manifestation of HRI. CLINICAL RELEVANCE: This study advances the current knowledge of HRI symptoms in farmworkers and moves beyond reporting individual symptoms by utilizing latent class analysis to identify how symptoms tend to co-occur together in this population. It acknowledges multiple symptoms occurring as a result of occupational heat exposure and highlights the importance of symptom recognition.

Contact networks in the emergency department: Effects of time, environment, patient characteristics, and staff role.

Emergency departments play a critical role in the public health system, particularly in times of pandemic. Infectious patients presenting to emergency departments bring a risk of cross-infection to other patients and staff through close proximity interactions or contacts. To understand factors associated with cross-infection risk, we measured close proximity interactions of emergency department staff and patients by radiofrequency identification in a working emergency department. The number of contacts (degree) is not related to patient demographic characteristics. However, the amount of time in close proximity (weighted degree) of patients with ED personnel did differ, with black patients having approximately 15 min more contact with staff than non-white patients. Patients arriving by EMS had fewer contacts with other patients than patients arriving by other means. There are differences in the number of contacts based on staff role and arrival mode. When crowding is low, providers have the most contact time with patients, while administrative staff have the least. However, when crowding is high, this differential is reversed. The effect of arrival mode is modified by the extent of crowding. When crowding is low, patients arriving by EMS had longer contact with administrative staff, compared to patients arriving by other means. However, when crowding is high, patients arriving by EMS had less contact with administrative staff compared to patients arriving by other means. Our findings should help designers of emergency care focus on higher risk situations for transmission of dangerous pathogens in an emergency department. For instance, the effects of arrival and crowding should be considered as targets for engineering or architectural interventions that could artificially increase social distances.

Use of text messaging for maternal and infant health: a systematic review of the literature.

Text messaging is an increasingly popular communication tool in health interventions, but has been little studied in maternal and infant health. This literature review evaluates studies of text messaging that may be applied to the promotion of maternal and infant health. Articles from peer-reviewed journals published before June 2012 were included if they were experimental or quasi-experimental studies of behaviors endorsed either by the American College of Obstetrics and Gynecology, the American Pediatrics Association, or the United States Preventive Services Task Force; included reproductive age women (12-50 years) or infants up to 2 years of age; and were available in English. Qualitative studies of text messaging specific to pregnant women were also included. Studies were compared and contrasted by key variables, including: design, time-period, study population, and results. Forty-eight articles were included, 30 of which were randomized controlled trials. Interventions vary greatly in effectiveness and soundness of methodology, but collectively indicate that there is a wide range of preventative behaviors that text message interventions can effectively promote, including smoking cessation, diabetes control, appointment reminders, medication adherence, weight loss, and vaccine uptake. Common methodological issues include not accounting for attention affect and not aligning text message content to measured outcomes. Those interventions that are based on an established theory of behavior change and use motivational as opposed to informational language are more likely to be successful. Building on the growing body of evidence for text message interventions reviewed here, as well as the growing popularity of text messaging as a medium, researchers should be able to use this technology to engage difficult to reach populations.

Alcoholism causes alveolar macrophage zinc deficiency and immune dysfunction.

RATIONALE: Alcohol use disorders cause oxidative stress in the lower airways and increase susceptibility to pneumonia and lung injury. Currently, no therapeutic options exist to mitigate the pulmonary consequences of alcoholism. OBJECTIVES: We recently determined in an animal model that alcohol ingestion impairs pulmonary zinc metabolism and causes alveolar macrophage immune dysfunction. The objective of this research is to determine the effects of alcoholism on zinc bioavailability and alveolar macrophage function in human subjects. METHODS: We recruited otherwise healthy alcoholics (n = 17) and matched control subjects (n = 17) who underwent bronchoscopy for isolation of alveolar macrophages, which were analyzed for intracellular zinc, phagocytic function, and surface expression of granulocyte-macrophage colony-stimulating factor receptor; all three of these indices are decreased in experimental models. MEASUREMENTS AND MAIN RESULTS: Alcoholic subjects had normal serum zinc, but significantly decreased alveolar macrophage intracellular zinc levels (adjusted means [SE], 718 [41] vs. 948 [25] RFU/cell; P < 0.0001); bacterial phagocytosis (adjusted means [SE], 1,027 [48] vs. 1,509 [76] RFU/cell; P < 0.0001); and expression of granulocyte-macrophage colony-stimulating factor receptor ß subunit (adjusted means [SE], 1,471 [42] vs. 2,114 [35] RFU/cell; P < 0.0001]. Treating alveolar macrophages with zinc acetate and glutathione in vitro increased intracellular zinc levels and improved their phagocytic function. CONCLUSIONS: These novel clinical findings provide evidence that alcohol abuse is associated with significant zinc deficiency and immune dysfunction within the alveolar space and suggest that dietary supplementation with zinc and glutathione precursors could enhance airway innate immunity and decrease the risk for pneumonia or lung injury in these vulnerable individuals.

Text4baby program: an opportunity to reach underserved pregnant and postpartum women?

Text4baby was launched in 2010 to promote healthy pregnancies and babies by the use of text messaging. The primary objective of this study was to assess factors related to the enrollment process and reception of text4baby. A prospective cohort study was conducted in two Women, Infant and Children clinics in Atlanta (April 2010-July 2011). Randomly selected pregnant and postpartum women (n = 468) were queried on cell phone use and instructed on text4baby enrollment. Self-enrollment issues were assessed at one-week follow-up (n = 351, 75.0 %), and message reception and reading patterns at two-month follow-up (n = 209, 44.7 %). Forty-two percent of the women had some college education and 82 % had household income <=$20,000. About half attempted text4baby self-enrollment (162/351), with enrollment success more likely among women with more education (80 % with some college vs. 62 % with less education), with household income above $10,000 (61 % < $10,000 vs. 83 % $10,001-$20,000 and 76 % > $20,000), and among women living in smaller households (77 % 1-3 members vs. 58 % > 3 members) (all p < 0.001). Among the 209 participants in the final follow-up contact, >90 % reported uninterrupted reception and regular reading of messages, and 88 % planned to continue using text4baby. Results also suggested that respondents who were younger (<26 year), less educated and had lower health literacy skills were more likely to have interrupted messages. Despite substantial interest in the text4baby program in an underserved population, innovative ways to help women with significant disadvantages enroll and receive uninterrupted messages are needed.

Retention of Agricultural Workers Participating in a Renal Longitudinal Study.

OBJECTIVES: The relationship between heat stress, chronic kidney diseases and acute kidney injury has been documented in cross-sectional studies with agricultural workers. However, only a few international studies have assessed renal function in agricultural workers longitudinally. Our research study, Occupational Heat Exposure and Renal Dysfunction (OHEaRD) is the first longitudinal study in the U.S. that monitored renal function in agricultural workers five times over the course of 32-months. The main objectives of this study were to evaluate the rate of retention and identify predictors associated with retention in a longitudinal study with agricultural workers. METHODS: In January 2020, we enrolled 119 Florida agricultural workers to observe on 5 workdays over 32 months. Retention was defined by the number of follow-up visits that a participant attended, the consistency of visit attendance, and attendance at the last visit. Participants were provided hemoglobin A1C, lipid panel, creatinine measurement, glomerular filtration rate (eGFR), blood pressure, and body mass index results and an incentive gift card were handed out to participants at each visit. RESULTS: Four enrollees did not participate on any workday, thus analysis concentrated on the remaining 115 participants. The majority of participants (64%) completed the 32-month study, 78% completed at least 4 visits, and 55% completed all 5 visits. The statistically significant predictors of higher retention among this study were being older in age (p=0.02), Mexican nationality (p=0.004), working in ferneries (p=0.009), more years working in agriculture (p=0.02), and higher total cholesterol (p=0.02). Appreciation for the health tests was associated with greater participation at the final visit (p=0.01). CONCLUSION: Retention in longitudinal studies is crucial to better understand kidney disease among agricultural workers, an understudied population. Participants reported valuing the access to health results, indicating that implementing point-of-care health screenings and providing the health results to each participant is a good retention strategy. There was some evidence that a participant living with or being related to a fellow co-participant could impact retention as they either showed up or missed visits together, suggesting recruiting from the same household may reduce retention.