No description available.

No description available.

No description available.

Allostatic load, or the “wear and tear” on the body due to stress, is thought to have a negative impact on length of pregnancy and contribute to health disparities in preterm birth. However, the magnitude of the effect on birth outcomes is unknown, in part due to questions of timing of measurement of allostatic load during pregnancy. This study used linear regression analysis of data from 156 pregnant women to test whether allostatic load is a predictor of length of gestation in the study sample, finding that third trimester allostatic load predicted length of gestation among women with full-term births. The study also compared allostatic load in each trimester to determine an optimal time of measurement for prediction of preterm birth. Findings were inconclusive because regardless of trimester of measurement, allostatic load was not a significant predictor of gestational length in the sample. Finally, the study compared allostatic load with scores on the Everyday Stressors Index, a psychosocial measure, to understand the relative benefits of allostatic load measurement during pregnancy. Neither was found to be a statistically significant predictor of preterm birth, so direct comparisons were not possible. Implications and suggestions for future research are discussed.

ABSTRACT The Implications of Chronic Stress on Obesity: Allostatic Load on Body Mass Index (BMI) Classification in the United States, NHANES 2005-2006 INTRODUCTION: In this modern environment, our world is reflecting an exponential increase in not only population, but in body size. Obesity is an overwhelming public health concern among the United States population. Research has shown there is a positive correlation between adiposity and stress. Allostatic load (AL) has been presented to be a consistent measure of chronic stress damage on the body. Yet, there is few studies exemplifying the presence AL on classification of body mass index (BMI). AIM: The aim of this study is to find a relationship between allostatic load (AL) and body mass index (BMI) classification in the United States adult population on a large national scale. This complex interaction can predetermine who among the US population will be at greater risk for excess adiposity following this psychoneuroendocrinology. METHODS: A representative sample size of n=3826 was gathered using NHANES data (2005-2006). Criteria for sample included all United States adults that had numerical values for 10 biomarkers chosen to represent chronic stress damage (allostatic load) along with individual body mass index (BMI). Allostatic load (low, high) and BMI classification (underweight to class III obese) were further categorized on severity and computed in SPSS to find significance between gradients of each variable (α=.05). Cross-sectional analysis and logistical regression (multivariate) were used to further decipher an association between allostatic load and BMI category. RESULTS: A strong positive correlation between allostatic load risk and BMI category was found (p<.001). Also among the variables in the study, significance was found within the strata of age, gender, race, smoking status and poverty income ratio (PIR). Findings show a strong statistically significant relationship between allostatic load and BMI. DISCUSSION: It is imperative to decipher the directional relationship between stress and obesity to provide effective treatment. Understanding the pathology of how stress affects adiposity could open the door for many clinical and public health interventions to eradicate a very preventable outcome. By addressing the effect of chronic stress, a new avenue of prevention can be developed to combat the growing obesity rates in the United States.

The current dissertation sought to examine stress in three different, but overlapping, ways. The first study examined how self-reported negative life events, in the aggregate and individually, are associated with cognitive performance. The results suggested that there was no significant relationship between the aggregate measures of self-reported negative life events and cognitive performance. On the other hand, several individual negative life events were associated with cognitive functioning. The findings support previous research indicating that using estimates of individual stressors rather than aggregate measures of stressors increases the predictive validity of stress measurement. The second study assessed the cross-sectional and longitudinal effects of bereavement on cognitive functioning. The cross-sectional results revealed that bereavement status alone was not associated with cognitive performance. On the other hand, there were several significant interactions between bereavement status and the background characteristics. The longitudinal results revealed that the bereaved individuals declined on the delayed naming recall task and there was a significant interaction between gender and bereavement on the delayed story recall task. Our results support the finding that bereavement is associated with poorer cognitive performance within certain subgroups (i.e., males and the young-old participants). The third and final study examined the effects of allostatic load (AL) on cognitive performance in bereaved and non-bereaved individuals over a twelve-month period post-bereavement. The cross-sectional findings suggested that the overall AL measure, the syndrome X (a collection of cardiovascular risk factors) and non-syndrome X measures (stress hormones), and the individual AL markers were associated with cognitive performance. Longitudinally, we were unable to find an association between the overall AL measure and cognitive performance. Taken together, the current findings suggest that there is an association between the multiple stress factors under investigation and cognitive performance. The cross-sectional results revealed that the individual negative life events (i.e., having less money to live on), bereavement, and the AL markers were associated with poorer cognitive performance. Furthermore, the results suggest that utilizing the individual life events and AL markers may be more informative when assessing cognitive functioning in the current samples compared to using the sum scores.

Perseverative cognition is the repetitive cognitive representation of a stressor, which includes the concepts of worry and rumination. These thoughts delay post-stress cardiovascular recovery, which may lead to an increased risk for cardiovascular disease. This may be due to the negative emotional content of perseverative cognition or because it involves cognitive effort. The aim of this study was to identify the unique influences of negative emotional content and cognitive effort during recovery. Participants (N = 120) were given a demanding task purportedly as a measure of intelligence and then given false negative feedback. Immediately following, participants engaged in one of four recovery instruction conditions: think about task performance, perform a cognitive load task, watch a distracting video, or remain quietly seated. EKG, impedance cardiography, and blood pressure were recorded throughout. Perseverative cognition and cognitive load both resulted in significantly less heart rate recovery compared to the distracting video. Higher test motivation and anxiety were related to more blunted reactivity and delayed recovery of respiratory sinus arrhythmia. Reduced recovery during perseverative cognition and cognitive effort indicate that the cognitive load produced by perseveration is the pernicious component that explains its link to increased risk for cardiovascular disease. Further, the relationship between motivation/anxiety and blunted reactivity and recovery suggest effort may be important in the link between perseverative cognition and cardiovascular disease.

Bacterial Vaginosis is an inbalance of vaginal flora which has been associated with increased risk of numerous gynecological and obstetric morbidities including increased risk of acquisition of HIV from an infected partner and increased risk of preterm delivery. Black race has been consistently identified as a risk factor for BV. Black women also suffer from significant disparities in most of the morbidities also associated with BV when compared to women of other ethnicities and races. Traditional predictors of BV such as douching practices and sexual behaviors do not fully account for the racial disparities in BV prevalence. Researchers have begun to explore the potential relationship between stress and BV. Also, perceived racism has been identified as a potential stressor contributing to the health outcomes of Black women. The purpose of this study was to test a predictive model of bacterial vaginosis among Black women. The Allostatic Load Model was the theoretical framework. Participants (N=94) completed a self administered questionnaire and interview including measures of perceived stress, preceived racism, behavioral responses to stress and specific behavioral responses to racism along with traditional predictors of BV. Measurement scales included the Cohen Perceived Stress Scale, the John Henryism Scale of Active Coping, the Everyday Perceived Racial Discrimination Index, the Experiences of Discrimination Scale and the Vines Telephone Administered Perceived Racism Scale (TPRS) which included a behavioral responses to racism subscale. Bacterial vaginosis was diagnosed utilizing a self-collected vaginal swab which was analyzed utilizing the BVBlue point of care testing kit. Twenty percent (N=19) of participants screened positive for bacterial vaginosis. Douching and sexual activity in the last three months and education were significantly associated with bacterial vaginosis. Age, income, hormonal contraceptive use and condom use were not associated with BV. Neither perceived stress nor perceived racism were associated with bacterial vaginosis. After logistic regression analysis, only education continued to be a significant predictor of BV. The lack of an association between BV and the main study variables may have been related to young age of the sample or the low rates of high perceived stress and high perceived racism. Perceived stress was positively associated with perceived racism and behavioral responses to stress. This association is likely a reflection of the stressful nature of perceived racism. Further research is needed to better understand how the stressful nature of racism and behavioral responses to stressors may influence health outcomes and if interventions can be utilized to promote adaptive behavioral responses.

L'anthropisation croissante et les changements globaux entrainent de nombreuses perturbations dans l'environnement conduisant à la dégradation, et même à la destruction d'habitat. Le modèle allostatique proposé par McEwen et Wingfield en 2003 permet de mieux appréhender les relations entre physiologie et réponses démographique dans le cadre de la physiologie de la conservation. A travers des approches expérimentales en milieux controlé et semi-naturel nous avons testé l'effet de d'un stress chronique sur les changements des traits d'histoires de vie et les paramétres physiologique chez le lézard vivipare (Zootoca vivipara). Nous discutons de la caractérisation de la charge allostatique et des effets à court terme et long terme d'un stress chronique et l'utilisation de la charge allostatique comme indicateur de la dégradation de l'habitat. Ce travail pourra être utilisé afin de mieux comprendre et prédire la dynamique des populations naturelles soumises aux changements globaux. / Increasing anthropogenic and global changes are causing many disturbances in the environment leading to degradation and even destruction of habitat. The allostatic model proposed by McEwen and Wingfield in 2003 provides a better understanding of the relationships between physiology and demographic responses within the framework of conservation physiology. Experimental approaches in controlled and semi-natural environments have tested the effect of chronic stress on changes in life histories and physiological parameters in the viviparous lizard (Zootoca vivipara). We discuss the characterization of allostatic charge and the short-term and long-term effects of chronic stress and the use of allostatic charge as an indicator of habitat degradation. This work can be used to better understand and predict the dynamics of natural populations subjected to global changes.

Sense of purpose in life, or the view that one’s life has direction and is guided by overarching life aims, has been found to predict better health outcomes across the adult lifespan, including better cognitive functioning and dementia risk, physical health, and improved longevity. This research is based on multi-study replications of large longitudinal datasets, as well as intensive measurement design to examine short-term (e.g., within-day, day-to-day) and long-term (years) associations between sense of purpose and markers of cognition and health. The first project used multistate survival modeling to evaluate the role of sense of purpose on transitions across cognitive states and death and was based on two large longitudinal datasets – the Rush Memory and Aging Project (MAP) and the Health and Retirement Study (HRS). More purposeful older adults were found to have lower prospective risk of developing mild cognitive impairment (and equivalent classification in HRS), later onset of impairment, and increased likelihood of improvement in cognitive functioning following MCI classification. These results were replicated across two independent longitudinal studies with disparate samples and measurement procedures. The second project examined longitudinal associations between sense of purpose in life and allostatic load in two nationally representative samples of American (HRS) and English (English Longitudinal Study of Ageing; ELSA) adults over age 50. Blood-based biomarkers of cardiovascular, metabolic, immune, and renal function, as well as anthropometric and physical markers such as lung function were used to compute overall scores representing allostatic burden. Sense of purpose in life was associated with lower overall level of allostatic load across measurement occasions in the two samples but did not predict rate of change or within-person fluctuations in allostatic burden across time. The third study investigated daily variations in sense of purpose and associations with daily cognitive performance using an ecological momentary assessment design. Multilevel models examined within- and between-person associations between end of day sense of purpose ratings and performance on five indices of cognitive functioning. Results showed no associations between daily ratings of purposefulness and performance on five cognitive tasks across a two-week period. Taken together, these findings advance existing theory and highlight important directions for the field moving forward. / Graduate / 2023-07-29