Neil Schneiderman

Cardiovascular Reactivity and Development of Preclinical and Clinical Disease States

Objective The objective of this review is to evaluate the evidence for the hypothesis that cardiovascular reactivity can predict the development of preclinical (elevated blood pressure, ventricular remodeling, carotid atherosclerosis) and/or clinical cardiovascular disease states. Methods A review of the literature was conducted examining prospective studies. Results Three large epidemiological studies with long-term follow-up periods (20 years or more) have found blood pressure responses to the cold pressor task to be predictive of subsequent essential hypertension in initially normotensive samples. Studies showing less consistent results have tended to use shorter-term follow-up periods. A larger body of literature demonstrates consistent associations between stress-related cardiovascular reactivity and blood pressure elevations in youth over the course of 1 to 6 years; such relationships have not been consistently shown among adult samples. Moderately consistent evidence points to a positive relationship between reactivity and other measures of subclinical disease (increased left ventricular mass and carotid atherosclerosis) among the few prospective studies that have examined these issues to date. A number of additional factors, however, such as baseline levels of disease risk and exposure to psychosocial stress, seem to moderate these relationships. Health status at baseline also seems to moderate the association between reactivity and clinical coronary heart disease in recent reports: two of three existing studies in initially healthy samples show no evidence of a relationship between reactivity and clinical outcomes, whereas three of four studies in samples with preexisting coronary heart disease or essential hypertension show a positive relationship between reactivity and subsequent disease states. Conclusions There is reasonable evidence to suggest that cardiovascular reactivity can predict the development of some preclinical states (eg, increased left ventricular mass and blood pressure) states and perhaps even new clinical events in some patients with essential hypertension or coronary heart disease. However, much more information is needed concerning moderating and potentially confounding variables before the robustness of the positive relationships can become clinically useful.

Prevalence of Major Cardiovascular Risk Factors and Cardiovascular Diseases Among Hispanic/Latino Individuals of Diverse Backgrounds in the United States

CONTEXT Major cardiovascular diseases (CVDs) are leading causes of mortality among US Hispanic and Latino individuals. Comprehensive data are limited regarding the prevalence of CVD risk factors in this population and relations of these traits to socioeconomic status (SES) and acculturation. OBJECTIVES To describe prevalence of major CVD risk factors and CVD (coronary heart disease [CHD] and stroke) among US Hispanic/Latino individuals of different backgrounds, examine relationships of SES and acculturation with CVD risk profiles and CVD, and assess cross-sectional associations of CVD risk factors with CVD. DESIGN, SETTING, AND PARTICIPANTS Multicenter, prospective, population-based Hispanic Community Health Study/Study of Latinos including individuals of Cuban (n = 2201), Dominican (n = 1400), Mexican (n = 6232), Puerto Rican (n = 2590), Central American (n = 1634), and South American backgrounds (n = 1022) aged 18 to 74 years. Analyses involved 15,079 participants with complete data enrolled between March 2008 and June 2011. MAIN OUTCOME MEASURES Adverse CVD risk factors defined using national guidelines for hypercholesterolemia, hypertension, obesity, diabetes, and smoking. Prevalence of CHD and stroke were ascertained from self-reported data. RESULTS Age-standardized prevalence of CVD risk factors varied by Hispanic/Latino background; obesity and current smoking rates were highest among Puerto Rican participants (for men, 40.9% and 34.7%; for women, 51.4% and 31.7%, respectively); hypercholesterolemia prevalence was highest among Central American men (54.9%) and Puerto Rican women (41.0%). Large proportions of participants (80% of men, 71% of women) had at least 1 risk factor. Age- and sex-adjusted prevalence of 3 or more risk factors was highest in Puerto Rican participants (25.0%) and significantly higher (P < .001) among participants with less education (16.1%), those who were US-born (18.5%), those who had lived in the United States 10 years or longer (15.7%), and those who preferred English (17.9%). Overall, self-reported CHD and stroke prevalence were low (4.2% and 2.0% in men; 2.4% and 1.2% in women, respectively). In multivariate-adjusted models, hypertension and smoking were directly associated with CHD in both sexes as were hypercholesterolemia and obesity in women and diabetes in men (odds ratios [ORs], 1.5-2.2). For stroke, associations were positive with hypertension in both sexes, diabetes in men, and smoking in women (ORs, 1.7-2.6). CONCLUSION Among US Hispanic/Latino adults of diverse backgrounds, a sizeable proportion of men and women had adverse major risk factors; prevalence of adverse CVD risk profiles was higher among participants with Puerto Rican background, lower SES, and higher levels of acculturation.

Validation of the insulin sensitivity index (ISI0,120): comparison with other measures ☆

The purpose of this study was to explore possible calculations using oral glucose tolerance test (OGTT) values in order to develop a simple measure of insulin sensitivity. We devised a formula for an insulin sensitivity index, ISI(0,120), that uses the fasting (0 min) and 120 min post-oral glucose (OGTT) insulin and glucose concentrations. It appears to be generalizable across a spectrum of glucose tolerance and obesity. Most importantly, our data show that ISI(0,120) correlates well, when applied prospectively in comparative studies, with the insulin sensitivity index obtained from the euglycemic hyperinsulinemic clamp (r = 0.63, P < 0.001). This correlation was demonstrably superior to other indices of insulin sensitivity such as the HOMA formula presented by Matthews, and performed comparably to the computerized HOMA index. Measurement of insulin sensitivity has traditionally been possible only in research settings because of the invasiveness and expense of the methods used. Clinical investigators have therefore sought more practical methods to obtain an index of insulin sensitivity. Such an index should approximate insulin sensitivity as measured by the euglycemic hyperinsulinemic clamp (M). We present ISI(0,120), a simple yet sensitive measure of insulin sensitivity which is adaptable for use in clinical settings as well as large epidemiologic studies.

Posttraumatic Stress Symptoms, Intrusive Thoughts, Loss, and Immune Function after Hurricane Andrew

Objective To examine the impact of and relationship between exposure to Hurricane Andrew, a severe stressor, posttraumatic stress symptoms and immune measures. Methods Blood draws and questionnaires were taken from community volunteer subjects living in the damaged neighborhoods between 1 and 4 months after the Hurricane. Results The sample exhibited high levels of posttraumatic stress symptoms by questionnaire (33% overall; 76% with at least one symptom cluster), and 44% scored in the high impact range on the Impact of Events (IES) scale. A substantial proportion of variance in posttraumatic stress symptoms could be accounted for by four hurricane experience variables (damage, loss, life threat, and injury), with perceived loss being the highest correlate. Of the five immune measures studied Natural Killer Cell Cytotoxicity (NKCC) was the only measure that was meaningfully related (negatively) to both damage and psychological variables (loss, intrusive thoughts, and posttraumatic stress disorder (PTSD). White blood cell counts (WBCs) were significantly positively related with the degree of loss and PTSD experienced. Both NKCC (lower) and WBC were significantly related to retrospective self-reported increase of somatic symptoms after the hurricane. Overall, the community sample was significantly lower in NKCC, CD4 and CD8 number, and higher in NK cell number compared to laboratory controls. Finally, evidence was found for new onset of sleep problems as a mediator of the posttraumatic symptom - NKCC relationship. Conclusions Several immune measures differed from controls after Hurricane Andrew. Negative (intrusive) thoughts and PTSD were related to lower NKCC. Loss was a key correlate of both posttraumatic symptoms and immune (NKCC, WBC) measures.

Design and Implementation of the Hispanic Community Health Study/Study of Latinos

PURPOSE The Hispanic Community Health Study (HCHS)/Study of Latinos (SOL) is a comprehensive multicenter community based cohort study of Hispanics/Latinos in the United States. METHODS The Study rationale, objectives, design, and implementation are described in this report. RESULTS The HCHS/SOL will recruit 16,000 men and women who self-identify as Hispanic or Latino, 18 to 74 years of age, from a random sample of households in defined communities in the Bronx, Chicago, Miami, and San Diego. The sites were selected so that the overall sample would consist of at least 2000 persons in each of the following origin designations: Mexican, Puerto Rican and Dominican, Cuban, and Central and South American. The study includes research in the prevalence of and risk factors for heart, lung, blood and sleep disorders, kidney and liver function, diabetes, cognitive function, dental conditions, and hearing disorders. CONCLUSIONS The HCHS/SOL will (1) characterize the health status and disease burden in the largest minority population in the United States; (2) describe the positive and negative consequences of immigration and acculturation of Hispanics/Latinos to the mainstream United States life-styles, environment and health care opportunities; and (3) identify likely causal factors of many diseases in a population with diverse environmental exposures, genetic backgrounds, and early life experiences.

Psychosocial factors predict CD4 and viral load change in men and women with human immunodeficiency virus in the era of highly active antiretroviral treatment.

Objective: Most previous longitudinal studies demonstrating relationships between psychosocial variables and human immunodeficiency virus (HIV) disease progression utilized samples of gay men accrued before the era of highly active antiretroviral treatment (HAART), without including viral load (VL) as an indicator of disease progression or assessing the impact of medication adherence. This study sought to determine whether psychosocial variables would predict both CD4 and VL changes in a diverse sample assessed entirely during the era of HAART and accounting for adherence effects. Methods: This longitudinal study assessed a multiethnic HIV+ sample (n = 177) of men and women in the midrange of illness (CD4 number between 150 and 500; no previous acquired immunodeficiency syndrome [AIDS]–defining symptom) every 6 months for 2 years. Hierarchical linear modeling was used to model change in CD4 and VL controlling for sociodemographics (age, gender, ethnicity, education) and medical variables (baseline CD4/VL, antiretroviral medications at each time point, adherence). Results: Baseline depression, hopelessness, and education predicted the slope of CD4 and VL. Avoidant coping and life event stress predicted VL change. Cumulative variables produced stronger relationships (depression, avoidant coping, and hopelessness with CD4/VL slope and life events stress with VL slope). High cumulative depression and avoidant coping were associated with approximately twice the rate of decline in CD4 as low scorers and greater relative increases in VL. Social support was not significantly related to CD4 or VL slope. Conclusions: Psychosocial factors contribute significantly to the variance in HIV disease progression (assessed through CD4 number and VL) in a diverse sample, accounting for adherence and do so in the era of HAART. HAART = highly active antiretroviral treatment; VL = viral load; HIV = human immunodeficiency virus; AIDS = acquired immunodeficiency syndrome; PI = protease inhibitor; HLM = hierarchical linear modeling; DR = decline ratio; SES = socioeconomic status; BDI = Beck Depression Inventory; BHS = Beck Hopelessness Scale; N/A = not applicable.

Emotional disclosure through writing or speaking modulates latent Epstein-Barr virus antibody titers.

Healthy Epstein-Barr virus (EBV) seropositive undergraduates (N = 57) completed a personality inventory, provided blood samples, and were randomly assigned to write or talk about stressful events, or to write about trivial events, during three weekly 20-min sessions, after which they provided a final blood sample. Individuals assigned to the verbal/stressful condition had significantly lower EBV antibody titers (suggesting better cellular immune control over the latent virus) after the intervention than those in the written/stressful group, who had significantly lower values than those in the written/trivial control group. Subjects assigned to the written/stressful condition expressed more negative emotional words than the verbal/stressful and control groups and more positive emotional words than the verbal/stressful group at each time point. The verbal/stressful group expressed more negative emotional words compared with the control group at baseline. Content analysis indicated that the verbal/stressful group achieved the greatest improvements in cognitive change, self-esteem, and adaptive coping strategies.

Social support, positive states of mind, and HIV treatment adherence in men and women living with HIV/AIDS.

Numerous studies have linked social support to better medication adherence among illness groups, but few have examined potential mechanisms for this relationship. Relationships were examined between social support, depression, positive states of mind (PSOM), and medication adherence among HIV positive men who have sex with men (n = 61) and women (n = 29) on highly active antiretroviral therapy. Depression and PSOM were evaluated as potential mediators of the relationship between support and adherence. Cross-sectional data showed that greater social support and PSOM related to better adherence whereas higher depression scores related to nonadherence. PSOM partially mediated the relationship between social support and adherence. PSOM may be an important mechanism through which social support is related to better medication adherence in this population.

Sensorimotor and cognitive consequences of middle cerebral artery occlusion in rats

Rats were subjected to either right proximal middle cerebral artery (MCA) occlusion or sham operation, and examined for an extended period on a battery of tests designed to measure simple motor function, sensorimotor integration and cognitive function. Rats with MCA occlusion showed extensive neuronal loss in the dorsolateral striatum and variable neuron loss in the parietal, temporal and frontolateral neocortex. MCA occluded animals exhibited significant impairments in tests of postural reflex, visual and tactile forelimb placing, locomotor coordination, and a test of simultaneous bilateral tactile extinction. The reflex and sensorimotor function deficits recovered to pre-operative levels by Day 30 post-ischemia. Five weeks following surgery, rats were tested in 2 versions of the Morris water task. Rats with MCA occlusion demonstrated significant impairments in their ability to navigate to a hidden platform, but were not significantly impaired on the visible (cued) version of the task. This general pattern of transient sensorimotor and reflex deficits, but with more persistent cognitive impairments, is similar to that seen in humans following MCA infarcts.

Protective effects of brain hypothermia on behavior and histopathology following global cerebral ischemia in rats

The present experiments were designed to assess whether brain hypothermia can reduce the behavioral and histopathological deficits associated with global forebrain ischemia. Animals were subjected to 12.5 min of four vessel occlusion (4VO) with moderate hypotension, and brain temperature maintained at either 37 degrees C (4VO-37) or 30 degrees C (4VO-30). Behavioral tests designed to assess forelimb reflexes and sensorimotor function were given on post-operative weeks 2 and 4. Beginning in week 5, the rats were trained on a variety of navigation problems in the Morris water maze. Histopathological examination of the tissue 2 months following reperfusion revealed that 4VO-37 animals sustained substantial cell death in hippocampal region CA1 and moderate damage to the dorsolateral neostriatum. 4VO-30 animals showed minimal cell death in CA1 and neostriatum. There were no group differences for any of the sensorimotor measures, or for acquisition performance on either the simple place task or visible platform version of the water maze. In contrast, during acquisition of the learning set task, the performance of 4VO-37 animals was impaired relative to either of the other groups, whereas the performance of 4VO-30 animals was not significantly different from the sham controls. These data suggest that moderate intra-ischemic brain hypothermia provides long-lasting protection from behavioral deficits as well as neuronal injury following transient global ischemia.