Nightly sleep duration predicts grade point average in the first year of college.

Academic achievement in the first year of college is critical for setting students on a pathway toward long-term academic and life success, yet little is known about the factors that shape early college academic achievement. Given the important role sleep plays in learning and memory, here we extend this work to evaluate whether nightly sleep duration predicts change in end-of-semester grade point average (GPA). First-year college students from three independent universities provided sleep actigraphy for a month early in their winter/spring academic term across five studies. Findings showed that greater early-term total nightly sleep duration predicted higher end-of-term GPA, an effect that persisted even after controlling for previous-term GPA and daytime sleep. Specifically, every additional hour of average nightly sleep duration early in the semester was associated with an 0.07 increase in end-of-term GPA. Sensitivity analyses using sleep thresholds also indicated that sleeping less than 6 h each night was a period where sleep shifted from helpful to harmful for end-of-term GPA, relative to previous-term GPA. Notably, predictive relationships with GPA were specific to total nightly sleep duration, and not other markers of sleep, such as the midpoint of a student's nightly sleep window or bedtime timing variability. These findings across five studies establish nightly sleep duration as an important factor in academic success and highlight the potential value of testing early academic term total sleep time interventions during the formative first year of college.

Sleep and Daily Social Experiences as Potential Mechanisms Linking Social Integration to Nocturnal Blood Pressure Dipping.

OBJECTIVE: Socially integrated individuals are at lower risk of cardiovascular disease morbidity and mortality compared with their more isolated counterparts. This association may be due, in part, to the effect of social integration on nocturnal blood pressure (BP) decline or "dipping," a physiological process associated with decreased disease risk. However, the pathways linking social integration with nocturnal BP dipping are unknown. We sought to replicate the association between social integration and BP dipping, and to test whether sleep characteristics (duration, regularity, continuity) and/or daily social interactions (frequency, valence) helped to explain the association. METHODS: A total of 391 healthy midlife adults completed an actigraphy assessment protocol that measured sleep. During four actigraphy assessment days, participants also completed ambulatory BP monitoring and ecological momentary assessment protocols that measured BP and social interactions at regular intervals throughout the day. Social integration was assessed via a questionnaire. RESULTS: Linear regression controlling for age, sex, race, education, and body mass index indicated that higher levels of social integration were associated with greater nocturnal BP dipping, as indicated by a smaller ratio of night/day mean arterial pressure (ß = -0.11, p = .031). Analyses of indirect effects suggested that this association was explained, in part, by greater sleep regularity among more integrated individuals. We did not find evidence for other hypothesized indirect effects. CONCLUSIONS: This was the first study to investigate sleep and social mechanisms underlying the link between social integration and nocturnal BP dipping. Because sleep regularity is modifiable, this pathway represents a potential intervention target to promote nocturnal BP dipping.

Do Positive Psychological Factors Equally Predict Resistance to Upper Respiratory Infections in African and European Americans?

Research has consistently shown that positive psychological constructs are linked to better physical health, but few studies have examined the role that race plays in this connection. We explored whether positive self-evaluations were equally protective against upper respiratory infection for 271 African American adults and 700 European American adults in a series of virus-exposure studies. Participants were assessed at baseline for psychological functioning and physical health, quarantined and exposed experimentally to a respiratory virus, and then monitored for infection and symptoms. Regression analyses revealed significant interactions between race and multiple positive psychological factors; several factors that were helpful to European Americans were unhelpful or even harmful to African Americans. Building on past work showing cross-cultural variation in the health correlates of affect, this study provides evidence that the health benefits of positive psychological constructs may not be universal and points to the need to explore factors that underpin these observed differential patterns.

Lack of Belonging Predicts Depressive Symptomatology in College Students.

Feeling a sense of belonging is a central human motivation that has consequences for mental health and well-being, yet surprisingly little research has examined how belonging shapes mental health among young adults. In three data sets from two universities (exploratory study: N = 157; Confirmatory Study 1: N = 121; Confirmatory Study 2: n = 188 in winter term, n = 172 in spring term), we found that lower levels of daily-assessed feelings of belonging early and across the academic term predicted higher depressive symptoms at the end of the term. Furthermore, these relationships held when models controlled for baseline depressive symptoms, sense of social fit, and other social factors (loneliness and frequency of social interactions). These results highlight the relationship between feelings of belonging and depressive symptoms over and above other social factors. This work underscores the importance of daily-assessed feelings of belonging in predicting subsequent depressive symptoms and has implications for early detection and mental health interventions among young adults.

Temporal Links Between Self-Reported Sleep and Antibody Responses to the Influenza Vaccine.

BACKGROUND: Growing evidence suggests that sleep plays an important role in immunological memory, including antibody responses to vaccination. However, much of the prior research has been carried out in the laboratory limiting the generalizability of the findings. Furthermore, no study has sought to identify sensitive periods prior to or after vaccination where sleep may have a stronger influence on antibody responses. METHODS: Eighty-three healthy young adults completed 13 days of sleep diaries and received the trivalent influenza vaccine on day 3 of the study. Measures of self-reported sleep duration, sleep efficiency, and subjective sleep quality were assessed on each day. Antibody levels to the influenza viral strains were quantified at baseline and 1 and 4 months following influenza vaccination. RESULTS: Shorter sleep duration, averaged over the collection period, was associated with fewer antibodies to the A/New Caledonia viral strain 1 and 4 months later, independent of baseline antibodies, age, sex, and cohort year. Analyses focused on nightly sleep on the days preceding and after the vaccination revealed that shorter sleep duration on the two nights before the vaccination predicted fewer antibodies 1 and 4 months later. Measures of self-reported sleep efficiency and subjective quality were unrelated to antibody responses to the influenza vaccination. CONCLUSION: These findings provide further support for an association between sleep duration and antibody responses to the influenza vaccine and suggest that perhaps sleep on nights prior to vaccination are critical. If replicated, these findings may support sleep as a target for enhancing vaccination efficacy.

Review of the Association Between Number of Social Roles and Cardiovascular Disease: Graded or Threshold Effect?

OBJECTIVE: There is increasing evidence for an inverse association between the number of social roles (e.g., spouse, friend, and neighbor) we engage in and our risk of disease, especially cardiovascular disease (CVD). Two mechanistic models have been proposed to explain this association. The social integration model refers to a graded association where every additional social role is associated with an increase in resistance to disease. The social isolation model refers to a threshold effect where the lack of a minimal criterion number of roles increases risk of disease. METHODS: We conducted a systematic review of prospective studies examining the association between number of social roles and CVD risk. RESULTS: When we include all studies assessing number of social roles, irrespective of whether associations are attributable to graded effects (social integration) and threshold effects (social isolation) or cannot be determined by the data presented, those holding fewer social roles were found to be at greater risk of CVD incidence, CVD mortality (evidence stronger for men than women), and greater progression of disease (only for short [≤5 years] follow-ups). However, closer analyses indicate that the association between a greater number of social roles and decreased CVD incidence was attributable to graded effects among men but to both effects among women. In contrast, the association of number of social roles and disease progression was driven by threshold effects (social isolation) for both sexes, whereas mortality studies included evidence for both effects. CONCLUSIONS: These results suggest underlying mechanisms linking social roles to different CVD outcomes.

Good Relationships With Parents During Childhood as Buffers of the Association Between Childhood Disadvantage and Adult Susceptibility to the Common Cold.

OBJECTIVE: Children reared by parents of low socioeconomic status (SES) go on to have elevated rates of physical health problems and premature mortality. However, many children reared in low-SES families remain healthy throughout the life-span. Here, secondary analyses of archival data tested the hypothesis that a positive relationship with parents during childhood acts as a buffer of the increased risk of adult susceptibility to infectious illness associated with low childhood SES. METHODS: One hundred seventy-six healthy adults reported their childhood SES and the quality of their relationships with their parents during childhood. Relationship quality was defined as parental care, love and support, lack of conflict with parents, and family cohesiveness. Afterward, participants were exposed to a respiratory virus and monitored in quarantine for 5 days for the development of a "common cold" as indicated by infection and objective markers of illness. RESULTS: The increased risk of developing a cold associated with being reared in a low SES household was attenuated by a positive relationship with parents during childhood (b(SE) = 0.08 (0.03), p = .010). This buffering of disease risk held up across the four components of relationship quality (p values < .05). The association was independent of adult SES, demographics, prechallenge immunity to the virus, current levels of neuroticism and stress, parental divorce during childhood, and number of siblings (p values < .05). CONCLUSIONS: Individuals with positive relationships with their parents during childhood are buffered from the increased risk of adult susceptibility to an infectious disease associated with low childhood SES.

Ten Surprising Facts About Stressful Life Events and Disease Risk.

After over 70 years of research on the association between stressful life events and health, it is generally accepted that we have a good understanding of the role of stressors in disease risk. In this review, we highlight that knowledge but also emphasize misunderstandings and weaknesses in this literature with the hope of triggering further theoretical and empirical development. We organize this review in a somewhat provocative manner, with each section focusing on an important issue in the literature where we feel that there has been some misunderstanding of the evidence and its implications. Issues that we address include the definition of a stressful event, characteristics of diseases that are impacted by events, differences in the effects of chronic and acute events, the cumulative effects of events, differences in events across the life course, differences in events for men and women, resilience to events, and methodological challenges in the literature.

Offspring of parents who were separated and not speaking to one another have reduced resistance to the common cold as adults.

Exposure to parental separation or divorce during childhood has been associated with an increased risk for physical morbidity during adulthood. Here we tested the hypothesis that this association is primarily attributable to separated parents who do not communicate with each other. We also examined whether early exposure to separated parents in conflict is associated with greater viral-induced inflammatory response in adulthood and in turn with increased susceptibility to viral-induced upper respiratory disease. After assessment of their parents' relationship during their childhood, 201 healthy volunteers, age 18-55 y, were quarantined, experimentally exposed to a virus that causes a common cold, and monitored for 5 d for the development of a respiratory illness. Monitoring included daily assessments of viral-specific infection, objective markers of illness, and local production of proinflammatory cytokines. Adults whose parents lived apart and never spoke during their childhood were more than three times as likely to develop a cold when exposed to the upper respiratory virus than adults from intact families. Conversely, individuals whose parents were separated but communicated with each other showed no increase in risk compared with those from intact families. These differences persisted in analyses adjusted for potentially confounding variables (demographics, current socioeconomic status, body mass index, season, baseline immunity to the challenge virus, affectivity, and childhood socioeconomic status). Mediation analyses were consistent with the hypothesis that greater susceptibility to respiratory infectious illness among the offspring of noncommunicating parents was attributable to a greater local proinflammatory response to infection.

A randomized pilot trial of a school-based psychoeducational intervention for children with asthma.

BACKGROUND: Asthma is a common childhood illness with high morbidity and mortality among minority and socio-economically disadvantaged children. Disparities are not fully accounted for by differences in asthma prevalence, highlighting a need for interventions targeting factors associated with poorer asthma control. One such factor is psychological stress. OBJECTIVE: Here, we examine the feasibility and acceptability of "I Can Cope (ICC)," a school-based stress management and coping intervention for children with asthma. METHODS: A parallel randomized pilot trial was conducted. One hundred and four low-income children (mean age 10 years; 54% male; 70% African American) with persistent asthma were recruited from 12 urban schools and randomized to the following: (a) ICC or one of two control conditions: (b) "Open Airways for Schools (OAS)"-an asthma education intervention or (c) no treatment. RESULTS: Seventy one percentage of eligible children participated in the study, with a dropout rate of 12%. ICC was rated as highly acceptable by participating children and parents. Preliminary efficacy data suggest that when compared with no treatment, ICC resulted in decreased symptoms of depression, perceived stress and child-reported symptoms of asthma, and improvements in sleep quality and child-reported asthma control. There were no intervention-related changes in objective measures of asthma morbidity. The magnitude of intervention effects on psychological function did not differ between the ICC and OAS groups. CONCLUSIONS: Results support the feasibility and acceptability of utilizing school-based interventions to access hard to reach children with asthma. Preliminary findings offer support for future, large-scale efficacy studies of school-based interventions designed to target multiple factors that contribute to asthma disparities.

Effectiveness of Stress-Reducing Interventions on the Response to Challenges to the Immune System: A Meta-Analytic Review.

BACKGROUND: There is consistent evidence showing an interplay between psychological processes and immune function in health and disease processes. OBJECTIVES: The present systematic review and meta-analysis aims to provide a concise overview of the effectiveness of stress-reducing psychological interventions on the activation of immune responses in both healthy subjects and patients. METHODS: Included are 3 types of challenges: in vivo, in vitro, and psychophysiological. Such challenges are designed to mimic naturally occurring immune-related threats. RESULTS: A systematic literature search was conducted using PubMed, EMBASE, and PsychInfo, resulting in 75 eligible studies. The risk of bias was assessed with the Cochrane risk-of-bias tool. Across all studies, a small-to-medium effect size was found for the effects of psychological interventions on optimization of the immune function (g = 0.33; 95% CI 0.22-0.43). While the largest effects were found for in vivo immune-related challenges (g = 0.61; 95% CI 0.34-0.88; especially on studies that incorporated skin tests and wound healing), studies incorporating psychophysiological challenges and in vitro immune-related stimulations similarly suggest more optimal immune responses among those receiving stress-reducing interventions (g = 0.28; 95% CI 0.15-0.42). CONCLUSION: These findings showed substantial heterogeneity depending on the type of challenge, the study populations, and the intervention types. These data demonstrate support for the effectiveness of stress-reducing psychological interventions in improving immunity in studies that tested immune function by means of incorporating an in vivo,in vitro, or psychophysiological challenge. Future research should more consistently incorporate challenges into the study design to gather more insights in the mechanisms underlying the optimized immune function following a psychological intervention. This is also relevant for clinical practice, as psychological interventions can possibly supplement, or at least partially replace, current drug treatments in various somatic conditions to reduce side effects.

Prenatal fine particulate exposure and early childhood asthma: Effect of maternal stress and fetal sex.

BACKGROUND: The impact of prenatal ambient air pollution on child asthma may be modified by maternal stress, child sex, and exposure dose and timing. OBJECTIVE: We prospectively examined associations between coexposure to prenatal particulate matter with an aerodynamic diameter of less than 2.5 microns (PM2.5) and maternal stress and childhood asthma (n = 736). METHODS: Daily PM2.5 exposure during pregnancy was estimated using a validated satellite-based spatiotemporally resolved prediction model. Prenatal maternal negative life events (NLEs) were dichotomized around the median (high: NLE ≥ 3; low: NLE < 3). We used Bayesian distributed lag interaction models to identify sensitive windows for prenatal PM2.5 exposure on children's asthma by age 6 years, and determine effect modification by maternal stress and child sex. RESULTS: Bayesian distributed lag interaction models identified a critical window of exposure (19-23 weeks' gestation, cumulative odds ratio, 1.15; 95% CI, 1.03-1.26; per interquartile range [1.7 µg/m3] increase in prenatal PM2.5 level) during which children concomitantly exposed to prenatal PM2.5 and maternal stress had increased risk of asthma. No significant association was seen in children born to women reporting low prenatal stress. When examining modifying effects of prenatal stress and fetal sex, we found that boys born to mothers with higher prenatal stress were most vulnerable (19-21 weeks' gestation; cumulative odds ratio, 1.28; 95% CI, 1.15-1.41; per interquartile range increase in PM2.5). CONCLUSIONS: Prenatal PM2.5 exposure during sensitive windows is associated with increased risk of child asthma, especially in boys concurrently exposed to elevated maternal stress.

Resilience and immunity.

Resilience is the process that allows individuals to adapt to adverse conditions and recover from them. This process is favored by individual qualities that have been amply studied in the field of stress such as personal control, positive affect, optimism, and social support. Biopsychosocial studies on the individual qualities that promote resilience show that these factors help protect against the deleterious influences of stressors on physiology in general and immunity in particular. The reverse is also true as there is evidence that immune processes influence resilience. Most of the data supporting this relationship comes from animal studies on individual differences in the ability to resist situations of chronic stress. These data build on the knowledge that has accumulated on the influence of immune factors on brain and behavior in both animal and human studies. In general, resilient individuals have a different immunophenotype from that of stress susceptible individuals. It is possible to render susceptible individuals resilient and vice versa by changing their inflammatory phenotype. The adaptive immune phenotype also influences the ability to recover from inflammation-induced symptoms. The modulation of these bidirectional relationships between resilience and immunity by the gut microbiota opens the possibility to influence them by probiotics and prebiotics. However, more focused studies on the reciprocal relationship between resilience and immunity will be necessary before this can be put into practice.

Prenatal Nitrate Exposure and Childhood Asthma. Influence of Maternal Prenatal Stress and Fetal Sex.

RATIONALE: Impact of ambient pollution upon children's asthma may differ by sex, and exposure dose and timing. Psychosocial stress can also modify pollutant effects. These associations have not been examined for in utero ambient nitrate exposure. OBJECTIVES: We implemented Bayesian-distributed lag interaction models to identify sensitive prenatal windows for the influence of nitrate (NO3-) on child asthma, accounting for effect modification by sex and stress. METHODS: Analyses included 752 mother-child dyads. Daily ambient NO3- exposure during pregnancy was derived using a hybrid chemical transport (Geos-Chem)/land-use regression model and natural log transformed. Prenatal maternal stress was indexed by a negative life events score (high [>2] vs. low [≤2]). The outcome was clinician-diagnosed asthma by age 6 years. MEASUREMENTS AND MAIN RESULTS: Most mothers were Hispanic (54%) or black (29%), had a high school education or less (66%), never smoked (80%), and reported low prenatal stress (58%); 15% of children developed asthma. BDILMs adjusted for maternal age, race, education, prepregnancy obesity, atopy, and smoking status identified two sensitive windows (7-19 and 33-40 wk gestation), during which increased NO3- was associated with greater odds of asthma, specifically among boys born to mothers reporting high prenatal stress. Cumulative effects of NO3- across pregnancy were also significant in this subgroup (odds ratio = 2.64, 95% confidence interval = 1.27-5.39; per interquartile range increase in ln NO3-). CONCLUSIONS: Prenatal NO3- exposure during distinct sensitive windows was associated with incident asthma in boys concurrently exposed to high prenatal stress.

Low childhood subjective social status and telomere length in adulthood: The role of attachment orientations.

Low subjective social status (SSS) in childhood places one at greater risk of a number of health problems in adulthood. Theoretical and empirical evidence indicates that exposure to supportive parenting may buffer the negative effects of low childhood SSS on adult health. Given the importance of supportive caregivers and close others for the development of attachment orientations throughout the lifespan, attachment theory may be important for understanding why some individuals are resilient to the negative effects of low childhood SSS on adult health while others are not. We examined if attachment anxiety and attachment avoidance altered the association between childhood subjective social status (SSS) and length of telomeres in white blood cells in adulthood. Shorter telomere length is associated with increased risk of age-related diseases including cancer, type 2 diabetes, and cardiovascular disease. Participants (N = 128) completed self-report measures of childhood SSS and attachment orientations, as well as a blood draw. We found that among those with low childhood SSS, low attachment anxiety was associated with longer telomere length in white blood cells in comparison to high attachment anxiety controlling for participant age, sex, race, body mass index, and adult SSS. Among those with high childhood SSS, low attachment anxiety was associated with a slight decrease in telomere length. Attachment avoidance was unrelated to length of telomeres. Such findings provide further evidence for the role that close relationships may have on buffering SSS related health disparities.

Sleep Habits and Susceptibility to Upper Respiratory Illness: the Moderating Role of Subjective Socioeconomic Status.

BACKGROUND: Sleep is a predictor of infectious illness that may depend on one's socioeconomic status (SES). PURPOSE: This study aimed to investigate the moderating effects of objective and subjective SES on sleep-clinical cold risk link and test whether nasal inflammation serves as a plausible biological pathway. METHODS: This study combined data (n = 732) from three viral challenge studies. Measures of self-reported sleep and objective and subjective measures of SES were obtained. Participants were quarantined and administrated rhinovirus (RV) or influenza virus and monitored over 5 (RV) or 6 (influenza) days for the development of a cold. Symptom severity, including mucus production and nasal clearance time, and levels of nasal cytokines (interleukin (IL)-6 and IL-1ß) were measured prior to administration and each day during the quarantined period. RESULTS: Subjective SES, but not objective SES, moderated associations between shorter sleep duration and increased likelihood of a clinical cold. Compared to ≥8-hour sleepers, ≤6-hour sleepers with low subjective SES were at increased risk for developing a cold (OR = 2.57, 95% CI 1.10-6.02). There was no association between sleep duration and colds in high subjective SES participants. Among infected individuals who reported low subjective SES, shorter sleep duration was associated with greater mucus production. There was no evidence that markers of nasal inflammation mediated the link between sleep duration and cold susceptibility among those reporting low subjective SES. CONCLUSION: Subjective SES may reflect an important social factor for understanding vulnerability to and protection against infectious illness among short sleepers.

Association of prenatal and early childhood stress with reduced lung function in 7-year-olds.

BACKGROUND: No prior study has examined associations between prenatal and early-life stress on childhood lung function or identified critical windows of exposure. OBJECTIVE: To prospectively examine associations between prenatal and early-life stress and childhood lung function. METHODS: Stress was indexed by a maternal negative life events (NLEs) score ascertained during pregnancy and between 1 and 2 years post partum. Spirometry was performed when children were a mean (SD) of 6.99 (0.89) years old. Associations of prenatal and early postnatal stress with spirometry z scores were examined in 199 children using linear regression. Effect modification by child sex was explored. RESULTS: Most mothers were minorities (65% Hispanic, 21% African American), had 12 years or less of education (67%), and did not smoke prenatally (78%). The highest level of prenatal stress (≥5 NLEs) was associated with lower levels of forced expiratory volume in 1 second (FEV1) (z score = -0.53, P = .03), forced vital capacity (FVC) (z score = -0.49, P = .04), and forced expiratory flow between 25% and 75% (FEF25%-75%) (z score = -0.68, P = .01) after covariate adjustment; effects were similar for postnatal stress considered separately. In sex-stratified analyses, high postnatal stress (≥5 NLEs) was associated with lower FEV1 (z score = -0.76, P = .01), FVC (z score = -0.77, P = .01), and FEF25%-75% (z score = -0.67, P = .02) in boys but not girls, although the interaction term was not significant (P for interaction >.10). CONCLUSION: These are the first prospective data that link perinatal stress with reduced child lung function. High levels of stress in the prenatal and postnatal periods were associated with symmetric reductions in FEV1 and FVC consistent with impaired lung growth. Given that lung function growth patterns are established by 7 years of age, these findings have lifelong implications.

Prenatal particulate matter exposure and wheeze in Mexican children: Effect modification by prenatal psychosocial stress.

BACKGROUND: Air pollution exposure in childhood is associated with greater incidence and exacerbation of asthma, particularly in children whose parents report high levels of psychological stress. However, this interaction has not been completely elucidated in pregnancy. OBJECTIVE: To examine whether the association between prenatal exposure to particulate matter no larger than 2.5 µm in diameter (PM2.5) and wheeze in children is modified by prenatal stress. METHODS: Mexican women were recruited during pregnancy (N = 552). Residential prenatal daily exposure to PM2.5 was estimated using a satellite-based spatiotemporally resolved prediction model and averaged over trimesters. Maternal stress was indexed by maternal negative life events (NLE) score (range 0-11) ascertained during mid to late pregnancy. NLE scores were dichotomized at the median as low (NLE score ≤ 3) and high (NLE score > 3) stress. Reports of ever wheeze and wheeze in the past 12 months (current wheeze) for children were obtained using the International Study of Asthma and Allergies in Childhood survey at 48 months. The association between prenatal PM2.5 and wheeze was analyzed using a modified Poisson regression and stratified by low vs high stress. RESULTS: Greater PM2.5 exposure during the first trimester was associated with increased risk of current wheeze among children with mothers reporting high prenatal stress (relative risk 1.35, 95% confidence interval 1.00-1.83, per interquartile range increase 3.8 µg/m3) but not among those reporting low stress (relative risk 0.84, 95% confidence interval 0.61-1.16, per interquartile range increase 3.8 µg/m3; P for interaction = .04). CONCLUSION: Increased prenatal stress enhanced the association between PM2.5 exposure in early pregnancy, and child wheeze at 48 months of age. It is important to consider chemical and nonchemical stressors together to more comprehensively characterize children's environmental risk.

Dispositional Affect Moderates the Stress-Buffering Effect of Social Support on Risk for Developing the Common Cold.

OBJECTIVE: The aim was to examine whether trait positive and negative affect (PA, NA) moderate the stress-buffering effect of perceived social support on risk for developing a cold subsequent to being exposed to a virus that causes mild upper respiratory illness. METHOD: Analyses were based on archival data from 694 healthy adults (Mage = 31.0 years, SD = 10.7 years; 49.0% female; 64.6% Caucasian). Perceived social support and perceived stress were assessed by self-report questionnaire and trait affect by aggregating responses to daily mood items administered by telephone interview across several days. Subsequently, participants were exposed to a virus that causes the common cold and monitored for 5 days for clinical illness (infection + objective signs of illness). RESULTS: Two 3-way interactions emerged-Support × Stress × PA and Support × Stress × NA. The nature of these effects was such that among persons with high trait PA or low trait NA, greater social support attenuated the risk of developing a cold when under high but not low perceived stress; this stress-buffering effect did not emerge among persons with low trait PA or high trait NA. CONCLUSIONS: Dispositional affect might be used to identify individuals who may be most responsive to social support and support-based interventions.

Sex differences in the association between stressor-evoked interleukin-6 reactivity and C-reactive protein.

Individuals differ consistently in the magnitude of their inflammatory responses to acute stressors, with females often showing larger responses than males. While the clinical significance of these individual differences remains unclear, it may be that greater inflammatory responses relate to increased systemic inflammation and thereby risk for chronic inflammatory disease. Here, we examined whether acute stressor-evoked interleukin (IL)-6 responses associate with resting levels of C-reactive protein (CRP), a marker of systemic inflammation, and whether this association differs by sex. Subjects were 57 healthy midlife adults (30-51years; 33% female; 68% white). Blood was drawn before and 30-min after two mental stress tasks: a multisource interference task and a Stroop color word task. Hierarchical regressions controlling for age, sex, race, and BMI tested whether stressor-evoked IL-6 responses were associated with resting CRP and whether this association differed by sex. Results indicated that sex and stressor-evoked IL-6 responses interacted to predict CRP (ΔR2=0.08, B=-1.33, ß=-0.39, p=0.02). In males, larger stressor-evoked IL-6 responses associated with higher CRP, whereas in females, stressor-evoked IL-6 responses showed a non-significant negative association with CRP. These findings indicate that inflammatory responses to acute stressors associate with resting levels of CRP; however, this association differs by sex. Previous literature suggests that there are sex differences in stressor-evoked IL-6 responses, but this is the first study to show sex differences in the relationship between acute inflammatory responses and systemic inflammation. The contribution of these sex differences to inflammatory disease risk warrants further investigation.