Associations of changes in fat free mass with risk for type 2 diabetes: Hispanic Community Health Study/Study of Latinos

AIMS

To determine whether loss of muscle mass (approximated using fat free mass [FFM]) is associated with risk for type 2 diabetes mellitus (T2DM) in Hispanic/Latino adults in the United States.

METHODS

Participants were Hispanic/Latino adults (18-74-year-olds) who completed Visit 2 of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL; multi-site, prospective cohort study; 6.1-year follow-up) and did not have T2DM at baseline (n = 6264). At baseline and Visit 2, FFM was measured using bioelectrical impedance analysis and fasting glucose, HbA1c, and fasting insulin were measured by examiners. Diabetes was defined according to American Diabetes Association criteria. Survey-weighted Poisson regression models examined the association of percent change in relative FFM (%ΔFFM) with incident prediabetes and T2DM. Survey-weighted multivariable regression models examined associations of %ΔFFM with changes in glucose and insulin measures.

RESULTS

Relative FFM declined by 2.1% between visits. %ΔFFM was inversely associated with incident prediabetes (p-for-trend = 0.001) and with changes in glucose and insulin measures (p-for-trend <0.0001). Findings were null, except for HOMA-IR, after adjustment for changes in adiposity measures. Associations were generally stronger for individuals with baseline overweight/obesity.

CONCLUSIONS

Reducing loss of FFM during adulthood may reduce prediabetes risk (primarily insulin resistance), particularly among individuals with overweight/obesity.

0609 Sleep Phenotypes in Middle-Aged and Older Hispanics/Latinos. Results from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Introduction

Identifying sleep phenotypes in the diverse and understudied US Hispanic/Latino population is critical to developing interventions and mitigating distal clinical outcomes (e.g. dementias).

Methods

Using latent class analyses (LCA), we identify empirically derived and clinically meaningful sleep phenotypes using data on community dwelling middle-aged/older adults (ages ≥45-years) from the HCHS/SOL (2008-2011) - Investigation of Neurocognitive Aging (n=6,377). Sleep variables used included Apnea/Hypopnea Index (AHI), percent time SpO2&lt;90%, Epworth Sleepiness Scale (ESS), Women’s Health Initiative Insomnia Rating Scale (WHIIRS), self-reported average sleep duration, restless legs symptoms, napping frequency, and sleep quality.

Results

Mean (M) age was 56.4±8.1 years, and 54.7% were female. Average AHI, ESS, WHIIRS, and sleep duration were 8.7±13.1, 6.0±5.0, 7.6±5.5, and 7.8±1.4, respectively, and 25.8% had zero percent time SpO2 &lt;90%. Fit statistics indicated that a four-class solution provided the best data fit. The derived classes, adjusting for age, sex, income, and acculturation, corresponded with four clinically meaningful groups: (1) 28.8% were asymptomatic [(M) AHI=0.8; (M) ESS=5.6; (M)WHIIRS=7.6; (M) sleep duration=7.8; 0% SpO2&lt;90%=74.1%], (2) 25.7 % were asymptomatic mild sleep apnea [(M) AHI=6.2; (M) ESS=3.8; (M) WHIIRS=2.9; (M) sleep duration=7.8; 0% SpO2&lt;90%=8.8%], (3) 19.4% were symptomatic sleep apnea [(M) AHI=25.6; (M) ESS=8.5; (M) WHIIRS=7.2; (M) sleep duration=7.7; 0% SpO2&lt;90%= 0.5%], and (4) 26.1% were insomnia [(M) AHI=5.7; (M) ESS=6.7; (M) WHIIRS=13.0; (M) sleep duration=7.8; 0% SpO2&lt;90%=10.3%]. Classification into groups 3 and 4 were primarily driven by elevated AHI and WHIIRS scores, respectively. The distribution of scores in the derived groups suggest variations relative to current clinical thresholds.

Conclusion

We identified 4-groups using LCA in a community-based sample of diverse U.S. Hispanic/Latino adults. Better characterization of sleep phenotypes for Hispanics/Latinos can help in developing targeted interventions studies and ameliorate health disparities.

Support

5R01AG048642-05; R21AG056952; R21HL140437.

0607 Clinical Phenotypes of OSA in Diverse Hispanics/Latinos: Results from the Hispanic Community Health Study/Study of Latinos

Introduction

Recent work on US non-Latino Whites and Europeans from clinical samples used obstructive sleep apnea (OSA) symptoms to generate OSA phenotypes for individuals with moderate-severe OSA and proposed between 3-5 clusters. Validating these clusters in a diverse Hispanic/Latino community-based population with different biopsychosocial characteristics is crucial for early OSA identification and more personalized treatment.

Methods

This work is based on baseline data from The Hispanic Community Health Study/Study of Latinos (HCHS/SOL). HCHS/SOL is a prospective cohort study designed using a multisite (Bronx, NY, Chicago, IL, Miami, FL, San Diego, CA) multistage probability sample. The subpopulation of interest included adults 18-74 years (unweighted n=1,623) meeting criteria for moderate-severe OSA symptoms (≥15 Apnea-Hypopnea index (AHI) events per hour). We performed latent class analysis (LCA) using 15 common OSA symptoms to identify phenotype clusters.

Results

Average age was 52.4 ± 13.9 years and 34.1% were female. Mean AHI was 33.8 ± 22.5 events per hour. Fit statistics and clinical significance suggested that a three-class solution provided best fit to the data. The symptom profiles were consistent with (1) a Minimally Symptomatic group (46.8%), (2) a Disturbed Sleep group (38.1%), and (3) a Daytime Sleepiness group (15.1%). Validation analyses using alternative hierarchical and partitioning algorithms also suggested support for a three-class solution.

Conclusion

Sleep apnea phenotypes among diverse Hispanics/Latinos were consistent with recent findings from the Sleep Apnea Global Interdisciplinary Consortium. However, we found notable differences in the prevalence of these clusters relative to Whites. This suggests that other biopsychosocial factors may be contributing to OSA phenotypes among Hispanics/Latinos. Identification of OSA phenotypes in Hispanics/Latinos could inform better sleep interventions and therapeutics and help better align public health resources.

Support

5R01AG048642-05; R21AG056952; R21HL140437.

The associations between anthropometric measurements and left ventricular structure and function: the Echo-SOL Study

OBJECTIVE

The objective of this study is to determine associations between anthropometry and echocardiographic measures of cardiac structure and function in Hispanic/Latinos.

METHODS

A total of 1,824 participants from ECHO-SOL were included. We evaluated associations between echocardiographic measures of left ventricular structure and function and anthropometric measures using multivariable-adjusted linear and logistic regression models adjusting for traditional cardiovascular risk factors.

RESULTS

The mean age was 56 ± 0.17 years, 57% were women. The mean body mass index (BMI) was 30 ± 9.4 kg m-2, waist circumference (WC) was 100 ± 18 cm, and waist-to-hip ratio (WHR) was 0.93 ± 0.15. Adjusted analysis showed that 5-unit increment in BMI and 5-cm increase in WC was associated with 3.4 ± 0.6 and 1.05 ± 0.05 g m-2.7 (p < 0.05 for both) higher left ventricular (LV) mass index, respectively. Similarly, 0.1-unit increment in WHR was associated with 2.0 ± 0.16 g m-2.7 higher LV mass index (p < 0.01). WHR was associated with 0.22 ± 0.08% decrease in ejection fraction (p < 0.05). Concomitantly, 5-unit increment in BMI and WC was associated with increased odds of abnormal LV geometry (odds ratio 1.40 and 1.16, p = 0.03 and <0.01, respectively); 0.1-unit increment in WHR was associated with increased odds of abnormal LV geometry (odds ratio 1.51, p < 0.01).

CONCLUSIONS

Among Hispanic/Latinos, higher anthropometric measures were associated with adverse cardiac structure and function.

Self-reported and accelerometer-measured physical activity by body mass index in US Hispanic/Latino adults: HCHS/SOL

The association between obesity and physical activity has not been widely examined in an ethnically diverse sample of Hispanic/Latino adults in the US. A cross-sectional analysis of 16,094 Hispanic/Latino adults 18–74 years was conducted from the multi-site Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Body mass index (BMI) was measured and categorized into normal, overweight, and obese; underweight participants were excluded from analyses. Physical activity was measured using the 16-item Global Physical Activity Questionnaire and by an Actical accelerometer. Minutes/day of physical activity and prevalence of engaging in ≥ 150 moderate–vigorous physical activity (MVPA) minutes/week were estimated by BMI group and sex adjusting for covariates. No adjusted differences were observed in self-reported moderate (MPA), vigorous (VPA), or MVPA across BMI groups. Accelerometry-measured MPA, VPA, and MVPA were significantly higher for the normal weight (females: 18.9, 3.8, 22.6 min/day; males: 28.2, 6.1, 34.3 min/day, respectively) compared to the obese group (females: 15.3, 1.5, 16.8 min/day; males: 23.5, 3.6, 27.1 min/day, respectively). The prevalence of engaging in ≥ 150 MVPA minutes/week using accelerometers was lower compared to the self-reported measures. Efforts are needed to reach the Hispanic/Latino population to increase opportunities for an active lifestyle that could reduce obesity in this population at high risk for metabolic disorders.

Psychosocial and Neurohormonal Predictors of HIV Disease Progression (CD4 Cells and Viral Load): A 4 Year Prospective Study

Most studies of psychosocial predictors of disease progression in HIV have not considered norepinephrine (NE), a neurohormone related to emotion and stress, even though NE has been related to accelerated viral replication in vitro and impaired response to antiretroviral therapy (ART). We therefore examined NE, cortisol, depression, hopelessness, coping, and life event stress as predictors of HIV progression in a diverse sample. Participants (n = 177) completed psychological assessment, blood draws [CD4, viral load (VL)], and a 15 h urine sample (NE, cortisol) every 6 months over 4 years. Hierarchical linear modeling (HLM) was used to model slope in CD4 and VL controlling for ART at every time point, gender, age, race, SES, and initial disease status. NE (as well as depression, hopelessness, and avoidant coping) significantly predicted a greater rate of decrease in CD4 and increase in VL. Cortisol was not significantly related to CD4, but predicted VL increase. To our knowledge, this is the first study relating NE, in vivo, to accelerated disease progression over an extended time. It also extends our previous 2 year study by relating depressed mood and coping to accelerated disease progression over 4 years.

Depressive symptoms linked to 1-h plasma glucose concentrations during the oral glucose tolerance test in men and women with the metabolic syndrome

AIMS

The addition of the 1-h plasma glucose concentration measure from an oral glucose tolerance test to prediction models of future Type 2 diabetes has shown to significantly strengthen their predictive power. The present study examined the relationship between severity of depressive symptoms and hyperglycaemia, focusing on the 1-h glucose concentration vs. fasting and 2-h glucose measures from the oral glucose tolerance test.

METHODS

Participants included 140 adults with the metabolic syndrome and without diabetes who completed a baseline psychobiological assessment and a 2-h oral glucose tolerance test, with measurements taken every 30 min. Depressive symptoms were assessed using the Beck Depression Inventory.

RESULTS

Multivariate linear regression revealed that higher levels of depressive symptoms were associated with higher levels of 1-h plasma glucose concentrations after adjusting for age, gender, ethnicity, BMI, antidepressant use and high-sensitivity C-reactive protein. Results were maintained after controlling for fasting glucose as well as for indices of insulin resistance and secretion. Neither fasting nor 2-h plasma glucose concentrations were significantly associated with depressive symptoms.

CONCLUSIONS

Elevated depressive symptoms in persons with the metabolic syndrome were associated with greater glycaemic excursion 1-h following a glucose load that was not accounted for by differences in insulin secretory function or insulin sensitivity. Consistent with previous findings, this study highlights the value of the 1-h plasma glucose measurement from the oral glucose tolerance test in the relation between depressive symptoms and glucose metabolism as an indicator of metabolic abnormalities not visible when focusing on fasting and 2-h post-oral glucose tolerance test measurements alone.

Influencing medication adherence among women with AIDS

This study examined the effects of a ten-session cognitive-behavioural stress management/expressive supportive therapy (CBSM+) intervention on adherence to antiretroviral medication. Although the intervention was not designed to influence adherence, it was theorized that improved coping and social support could enhance adherence. Women with AIDS (N = 174) in Miami, New York and New Jersey, USA, were randomized to a group CBSM+ intervention or individual control condition. Participants were African American (55%), Latina (18%) and Caribbean (18%) with drug (55%) and/or alcohol (32%) histories. Participants were assessed on self-reported medication adherence over seven days, HIV-related coping strategies and beliefs regarding HIV medication. Baseline overall self-reported adherence rates were moderate and related to coping strategies and HIV medication beliefs. Low adherent (80%) participants in the intervention condition increased their mean self-reported medication adherence (30.4% increase, t44 = 3.1, p < 0.01), whereas low adherent women in the control condition showed a non-significant trend (19.6% increase, t44 = 2.0, p > 0.05). The intervention did not improve adherence in this population; conditions did not differ significantly on self-reported adherence. Low adhering intervention participants significantly decreased levels of denial-based coping (F1,88 = 5.97, p < 0.05). Results suggest that future interventions should utilize group formats and address adherence using coping and medication-knowledge focused strategies.

Perceived stress is associated with CD4+ cell decline in men and women living with HIV/AIDS in Spain

This study assessed whether perceived stress as measured by the Perceived Stress Scale (PSS) was associated with a decline in CD4+ cell counts over a six-month period in 59 men and 41 women living with HIV-1. Participants underwent psychological and medical assessment at the study entry (baseline) and again at six months post-baseline. In a hierarchical regression model controlling for sociodemographic (e.g. age, gender, education, income) and disease-related variables (e.g. duration of antiretroviral treatment, antiretroviral treatment and adherence, CD4+ cell count and viral load), perceived stress was associated with the decline in CD4+ cell count over the six-month period. These findings suggest perceived psychosocial stress is associated with CD4+ cell count decline independent of sociodemographic factors and disease status among men and women on antiretroviral medication for HIV/AIDS.

Distress, denial, and low adherence to behavioral interventions predict faster disease progression in gay men infected with human immunodeficiency virus

This study examined psychological prediction of 2-year disease progression in gay men after finding out their human immunodeficiency virus (HIV) serostatus. Psychological and immune status of asymptomatic gay men who did not know their HIV serostatus was monitored during the 5 weeks before and after serostatus notification. The men were randomly assigned to an exercise. cognitive-behavioral stress-management intervention, or control group. At 2-year follow-up for the 23 men who turned out to be seropositive. 9 had developed symptoms, including 5 with acquired immune deficiency syndrome--4 of whom died. Distress at diagnosis, denial (5 weeks post-diagnosis minus pre-diagnosis). and low adherence during interventions were significant predictors of 2-year disease progression. Denial and adherence remained significant predictors of disease progression even after controlling for CD4 number at entry. Furthermore. change in denial was significantly correlated with immune status 1 year later; l-year immune status was significantly correlated with 2-year disease progression. The present study therefore demonstrates significant relations between psychological variables on the one hand and both immune measures and HIV-1 disease progression on the other. We conclude that distress, denial, and low protocol compliance predict subsequent disease progression.

Aberrant parasympathetic and hemodynamic function distinguishes a subgroup of psychologically distressed individuals with asymptomatic type-I diabetes mellitus

In a previous study, a subgroup of asymptomatic insulin-dependent diabetic individuals (termed IDDM-2) were identified on the basis of diminished parasympathetic cardiac input and elevated heart rate at rest. When compared to another group of asymptomatic IDDM participants (termed IDDM-1), and a nondiabetic healthy control group, the IDDM-2 group displayed elevated blood pressure, supported by elevated total peripheral resistance. Measures of psychological regulation were also taken in this study, and form the basis of this article, which examined whether these IDDM-2 patients differed from the other two groups on these measures. The possible role of glycemic control, IDDM duration, and number of somatic complaints among group differences in psychological regulation was also examined. The IDDM-2 group reported increased psychological distress, as reflected by increased dysphoric or depressive symptoms, trait anxiety, perceived stress, and cynical hostility, as well as decreased optimism and interpersonal, but not family, social support. Glycemic control did not account for any of the group differences in psychological regulation. However, group differences in dysphoria and anxiety were accounted for by differences in somatic complaints, whereas differences in interpersonal social support were accounted for by IDDM duration. Moreover, none of the variables investigated accounted for the diminished optimism of the IDDM-2 group. Therefore, in individuals with IDDM, who would otherwise be considered, after medical examination, as no different from other asymptomatic IDDM individuals, the combination of diminished parasympathetic cardiac input and elevated heart rate was associated with aberrant alterations of both hemodynamic and psychological functioning; the increased psychological distress in these individuals may be influenced, in part, by increased diabetes duration and number of somatic symptoms.

The impact of improved self-efficacy on HIV viral load and distress in culturally diverse women living with AIDS: the SMART/EST Women's Project

The purpose of the present study was to determine whether changes in self-efficacy over time would be related to changes in disease progression markers (CD4, viral load) in a sample of women with AIDS. A self-efficacy measure was developed and two sub-scales emerged via factor analysis of 391 HIV-positive women: AIDS Self-efficacy and Cognitive Behavioral Skills Self-efficacy. Subsequently, the sub-scales and an additional adherence self-efficacy item were given to 56 HIV-positive women who were measured at two time points three months apart. Half of these women were randomly assigned to a CB intervention and half to a low intensity comparison condition. Increases in AIDS Self-efficacy over the three-month period were significantly related to increases in CD4 and decreases in viral load. Similarly, increases in Cognitive Behavioral Skills Self-efficacy were significantly related to decreases in distress over time. Findings were maintained within the intervention group alone. Interestingly, increases in cognitive behavioral skills self-efficacy and increases in the self-efficacy adherence item were also significantly related to decreases in viral load. Implications of the findings and suggestions for future research are discussed.

Psychosoziale Faktoren bei koronarer Herzkrankheit - wissenschaftliche Evidenz und Empfehlungen für die klinische Praxis

Psychosocial risk factors like low socio-economic status, lack of social support and social isolation, chronic work or family stress, as well as negative emotions, e. g. depression and hostility, contribute significantly to the development and adverse outcome of coronary heart disease (CHD). Negative effects of psychosocial risk factors are conveyed via behavioural pathways including unhealthy lifestyle, e. g. food choice, smoking, sedentary life, inadequate utilisation of medical resources, and psychobiological mechanisms like disturbed autonomic and hormonal regulation: all these factors contribute to metabolic dysfunction and inflammatory and haemostatic processes, which are directly involved in the pathogenesis of CHD. Interventions to improve pychosocial factors are available and have demonstrated positive effects on risk factors and - at least in part - on CHD morbidity and mortality. The prevention of CHD should therefore include screening for psychosocial risk factors and adequate interventions. Recommedations for the screening of risk factors, behavioural change and further management of psychosocial risk factors in clinical practice are pointed out.

Circulating levels of glucocorticoid hormones in WHHL and NZW rabbits: circadian cycle and response to repeated social encounter

Social environment influences the progression of atherosclerosis in an important experimental model of disease, the Watanabe Heritable Hyperlipidemic rabbit (WHHL). Although the hypothalamic-pituitary-adrenocortical (HPA) system is likely to play an important role in the behavioral modulation of disease, relatively little is known about the glucocorticoid responses in these animals, or in other strains of rabbits. The purpose of the present study was to: (1) evaluate the rabbit glucocorticoid circadian rhythm, (2) compare plasma cortisol and corticosterone responses to social stress, and (3) examine strain differences (i.e., WHHL vs. New Zealand White (NZW)) in rabbit glucocorticoid responses to assess whether WHHLs have an aberrant HPA system. It was found that male rabbits secrete both corticosterone and cortisol in a circadian rhythm that peaks in the afternoon and reaches a nadir at 0600 h, i.e., approximately 12 h out-of-phase with the human glucocorticoid rhythm. Both glucocorticoids responded similarly to social stress induced by repeated daily 4 h pairings with another male rabbit; after 10 days of pairings, glucorticoid values were significantly correlated with the amount of defensive agonistic behavior exhibited. Finally, there were no significant strain differences in glucocorticoid circadian rhythms, baselines, or responses to social stress. These data suggest that glucocorticoid responses (i.e., circadian rhythms, responses to social stress) in the WHHL are similar to glucocorticoid responses in standard laboratory white rabbits.

Gender differences in TNF-alpha levels among obese vs nonobese Latino children

OBJECTIVE

To examine the relationships between TNF-alpha, obesity, and insulin resistance among prepubescent children.

DESIGN

Cross-sectional study.

SETTING AND SUBJECTS

Data were collected from 112 nondiabetic Latino schoolchildren from public schools in three South Florida communities. Of the enrolled participants, 43.8% were obese (BMI 95th percentile) and 51.8% presented with a family history of type 2 diabetes mellitus (T2DM). With one exception, all demonstrated normal glucose tolerance.

INTERVENTIONS

Plasma TNF-alpha levels were determined with enzyme-linked immunosorbance assay (ELISA). Homeostasis model assessment (HOMA-IR) was calculated as an index of insulin resistance. Mean levels of TNF-alpha among obese vs nonobese children were compared with a one-way analysis of variance with two groups, and the association between TNF-alpha and HOMA-IR was assessed with a Pearson's correlation.

RESULTS

Higher circulating TNF-alpha levels were revealed among nonobese vs obese children. Nonobese girls demonstrated higher TNF-alpha levels than obese girls, whereas there were no significant differences for boys. There were no significant differences after stratifying for family history of T2DM. There was a modest relationship between increased TNF-alpha levels and decreased insulin resistance.

CONCLUSIONS

The observed elevated circulating TNF-alpha concentrations among leaner participants may reflect an inflammatory process that has been associated with higher levels of physical fitness in both adults and prepubescent children. This effect may remain stronger for prepubescent girls, and the mechanism may be attenuated by the hormonal changes that occur with the onset of puberty.

A brief sexual barrier intervention for women living with AIDS: acceptability, use, and ethnicity

Interventions aimed at reducing sexual transmission of human immunodeficiency virus/sexually transmitted diseases (HIV/STDs) have focused primarily on male condom use among seronegative men and women. However, female-controlled sexual barriers (female condoms and vaginal microbicides) offer women living with acquired immunodeficiency syndrome (AIDS) alternative methods to protect themselves and others from disease transmission. A pilot behavioral intervention was conducted to increase sexual barrier use and enhance and assess factors related to acceptability. Participants (N = 178) were drawn from the Stress Management and Relaxation Training with Expressive Supportive Therapy (SMART/EST) Women's Project, a multisite phase III clinical trial for women living with AIDS (Miami, FL; New York City, NY; Newark, NJ). Intervention participants (n = 89) were matched for age and ethnicity with control condition participants (n = 89). Women were African American (52%), Haitian (15%), Hispanic (19%), Caucasian (10%), and other ethnicities (4%). The intervention condition received barrier products (male and female condoms and spermicides based on nonoxynol-9 in the form of vaginal gel, film, and suppositories) during three sessions held over 3 months. Data on barrier use and acceptability were analyzed at baseline and 3 and 9 months postintervention. Use of N-9 spermicides on a trial basis increased significantly by 3 months in the intervention conditions (22%-51%, P <.05). Cultural differences in acceptability were greatest between Haitian women and women in other ethnic groups. Exposure to this pilot behavioral intervention was associated with increased acceptability and use of chemical barriers without decreased use of male condoms.

Relative preservation of natural killer cell cytotoxicity and number in healthy AIDS patients with low CD4 cell counts

OBJECTIVE

This study examines whether there may be an immune component that protects a relatively rare group of HIV-infected people with very low CD4 cell counts (< or = 50 x 10(6)/l) who have prolonged asymptomatic periods.

DESIGN/METHODS

Three groups were recruited in Miami: (i) healthy low CD4 cell count patients (HLC; n = 30) who, for 9 months had < 50 x 10(6) CD4 cells/l, were asymptomatic and were not on protease inhibitors during that time; (ii) HIV comparison group (Comp; n = 60) who had CD4 cell counts predominantly 150 x 10(6) to 400 x 10(6)/l and never had AIDS Category C symptoms; this group was also followed for CD4 cell count and viral load change over 6 months; and (iii) healthy community controls (n = 33). The study was replicated at the University of California at Los Angeles (UCLA) with HLC (n = 31) versus HIV-negative laboratory controls (n = 28).

RESULTS

The HLC patients were significantly higher than the Comp group on natural killer cell cytotoxicity (NKCC) and natural killer cell number (NK#) despite their lower CD4 cell numbers and higher viral loads. In fact, there was no difference between the HLC group and the healthy community control group in NK# or NKCC. The NK findings were replicated at UCLA. A retrospective analysis showing that higher NKCC was related to fewer prior symptoms in the HLC group, and prospective analysis in the Comp group showing that NK# predicted a lower increase in viral load over 6 months further supported the importance of NK# and NKCC.

CONCLUSIONS

Non-specific cellular immunity may be a factor protecting the health of HIV sero-positive individuals with very low CD4 cell counts.

Piecewise latent growth curve modeling of systolic blood pressure reactivity and recovery from the cold pressor test

Latent growth curve methodology was used to model systolic blood pressure reactivity and recovery from the cold pressor test. A piecewise regression approach permitted the separate but simultaneous modeling of the two components (reactivity and recovery) of the stress process. Data came from a study of 99 participants classified on the basis of gender, ethnicity, and family history of hypertension. Their systolic blood pressure was assessed at rest, during the cold pressor test, and during a task recovery period. A measure of task appraisal and readings from ambulatory blood pressure monitoring during a workday were also examined. The article illustrates a step-by-step approach to modeling reactivity and recovery. Results indicated that both reactivity and recovery were associated with subsequent systolic blood pressure at work.

Effects of gender and age on the cardiac baroreceptor reflex in hypertension

The present study examined whether alterations in the cardiac baroreceptor reflex in hypertension may be a function of constitutional differences associated with gender and age. These hypotheses were tested using a cross-sectional design that compared 20 normotensive and 21 hypertensive men and women of varying age for differences in baroreceptor reflex sensitivity and response latency for heart rate, obtained using a modified bolus phenylephrine (Oxford) method. Relative to their respective normotensive controls, baroreceptor reflex sensitivity was reduced in hypertensive men, but not in hypertensive women. Among normotensive subjects, men had greater baroreceptor reflex sensitivity than women. Independent from the effects associated with differences in blood pressure, age was not a significant predictor of reduction in baroreceptor reflex sensitivity. However, a combination of high blood pressure and older age was associated with a significant increase in baroreceptor reflex response time. In summary, gender and aging interacted with hypertension to alter two different aspects of the baroreceptor reflex. These results provide a preliminary indication that a decline in arterial baroreflex sensitivity may be more specific to hypertension in men than in women. Prolongation in baroreflex response latency in older hypertensive subjects also suggested that aging and hypertension may have a synergistic effect on cardiac parasympathetic function.

Modeling preclinical cardiovascular risk for use in epidemiologic studies: Miami community health study

To develop a method for assessing preclinical cardiovascular disease risk, models of resting cardiovascular regulation and of insulin metabolic syndrome were derived from information collected from 1991 to 1996 in a culturally heterogeneous sample of 319 healthy men and women (aged 25-44 years) from Miami-Dade County, Florida. The model of resting cardiovascular regulation used 8 noninvasive measures of autonomic and cardiovascular function. Three factors were derived: 1) parasympathetic, 2) inotropy, and 3) systemic vascular resistance. The model of insulin metabolic syndrome used 12 measures assessing body mass, insulin, glucose, and lipid metabolism. Four factors were derived: 1) body mass and fat distribution, 2) glucose level and regulation, 3) insulin level and regulation, and 4) plasma lipid levels. Analyses of the association of the two models revealed that subjects with lower cardiac contractility had greater body mass, higher fasting and postload insulin and glucose levels, and lower insulin sensitivity. Subjects with greater vascular resistance had greater body mass, higher total cholesterol and triglyceride levels, and lower high density lipoprotein cholesterol levels. These findings indicate that preclinical cardiovascular disease risk may involve pathophysiologic processes in which cardiac inotropic and vasodilatory functions are linked to specific aspects of insulin metabolic syndrome.

Autonomic and cardiovascular function in HIV spectrum disease: early indications of cardiac pathophysiology

Autonomic dysfunction in persons with acquired immune deficiency syndrome (AIDS) has been reported previously but its incidence in early stage HIV infection and its relation to cardiovascular function have not been fully examined. The present study evaluated cardiovascular and autonomic function in 55 HIV-seronegative, and 52 HIV-asymptomatic and 31 HIV-symptomatic seropositive men. Measures of hemodynamic and autonomic function were obtained at rest and during a standardized battery of autonomic tests. Results were compared across groups while controlling for age, body mass, and physical activity. Analyses indicated that measures of autonomic function did not differ among groups. However, at rest, both HIV seropositive groups exhibited diminished stroke volume and elevated diastolic blood pressure, albeit within normotensive levels. In addition, the ability to sustain a blood pressure response during prolonged challenge and the relationship between stroke volume and baroreceptor/vagal responsiveness were disrupted in the HIV-symptomatic group. Therefore, in the pre-AIDS stages of infection, autonomic functioning appeared intact; yet alterations in baroreceptor/vagal function associated with depressed myocardial function may be an early warning signal reflecting cardiovascular pathological processes potentially exacerbated by HIV spectrum disease.

Health psychology: psychosocial and biobehavioral aspects of chronic disease management

Psychosocial factors appear to impact upon the development and progression of such chronic diseases as coronary heart disease, cancer, and HIV/AIDS. Similarly, psychosocial interventions have been shown to improve the quality of life of patients with established disease and seem to influence biological processes thought to ameliorate disease progression. Small-scale studies are useful for specifying the conditions under which psychosocial factors may or may not impact quality of life, biological factors, and disease progression. They are also useful for informing us about the conditions under which psychosocial interventions can serve as adjuvants (e.g. adherence training) to medical treatments. Only large-scale clinical trials, however, can determine the extent to which these psychosocial interventions may impact morbidity and mortality.

Cognitive-behavioral stress management reduces distress and 24-hour urinary free cortisol output among symptomatic HIV-infected gay men

BACKGROUND

Stress management interventions can reduce symptoms of distress as well as modulate certain immune system components in persons infected with human immunodeficiency virus (HIV). These effects may occur in parallel with reductions in hypothalamic-pituitary-adrenal (HPA) axis hormones such as cortisol, which has been related in other work to a down-regulation of immune system components relevant to HIV infection. The present study tested the effects of a multimodal cognitive-behavioral stress management (CBSM) intervention on 24-hour urinary free cortisol levels and distressed mood in symptomatic HIV+ gay men.

METHODS

Symptomatic HIV-infected gay men who were randomized to either a 10-week group-based CBSM intervention or a 10-week wait-list period provided psychological responses and urine samples pre-post intervention.

RESULTS

Of the 59 participants providing matched questionnaire data, men assigned to CBSM (n = 40) showed significantly lower posttreatment levels of self-reported depressed affect, anxiety, anger, and confusion than those in the wait-list control group (n = 19). Among the 47 men providing urine samples (34 CBSM, 13 controls), those assigned to CBSM revealed significantly less cortisol output as compared to controls. At the individual level, depressed mood decreases paralleled cortisol reductions over this period across the entire sample.

CONCLUSION

A time-limited CBSM intervention reduced distress symptoms and urinary free cortisol output in symptomatic HIV+ gay men and greater reductions in some aspects of distress, especially depressed mood, paralleled greater decreases in cortisol over the intervention period. If persisting stressors and depressed mood contribute to chronic HPA axis activation in HIV-infected persons, then interventions such as CBSM, which teaches them to relax, alter cognitive appraisals, use new coping strategies, and access social support resources, may decrease distress and depressed mood and normalize HPA axis functioning.

Cardiovascular responsivity to stress in adolescents with and without persistently elevated blood pressure

OBJECTIVES

The goal of this study was to compare the cardiovascular responses to behavioural stressors of three groups of adolescents who differed in blood pressure status across assessments.

DESIGN

Casual blood pressure of adolescents who were identified as having elevated blood pressure during a school screen was re-evaluated in the laboratory. The adolescents were classified into two groups: (i) those with consistently elevated blood pressure across school and laboratory assessments and (i) those with labile blood pressure whose blood pressure in the laboratory was below 130/80 mmHg. A comparison group of adolescents with consistently normal blood pressure was also included.

METHODS

Cardiovascular parameters were assessed during rest and during two behavioural stressors, the evaluated speaking task and the mirror tracing task.

RESULTS

Adolescents with elevated blood pressure were more vascularly responsive across stressors than adolescents with labile blood pressure, who, in turn, were more reactive than adolescents with normal blood pressure.

CONCLUSIONS

These results suggest that vascular reactivity to behavioural stressors may be useful in predicting risk of hypertension because of its sensitivity in distinguishing adolescents with consistently elevated blood pressure from those with labile blood pressure and those with normal blood pressure.

Afferents to the central nucleus of the amygdala and functional subdivisions of the periaqueductal gray: neuroanatomical substrates for affective behavior

Evidence suggests the periaqueductal gray (PAG) is involved in the integration of behavioral and autonomic components of affective behavior. Our laboratory has shown that electrical stimulation of the ventrolateral periaqueductal gray (vl PAG) versus the dorsolateral periaqueductal gray (dl PAG), in the rabbit, elicits two distinct behavioral/cardiorespiratory response patterns. Furthermore, evidence suggests that the amygdaloid central nucleus (ACe) may influence cardiovascular activity during emotional states. The purpose of this study was to delineate the topography and determine the origin of forebrain projections to the PAG and the ACe, as well as commonalties and differences in the pattern of afferents. Examination of common afferents may lend insights into their function as components of a forebrain system regulating autonomic activity during emotional states. Separate retrograde tracers were injected into functional subdivisions of the PAG and the ACe in rabbits. PAG injections led to neuronal labeling in numerous cortical regions including the ipsilateral medial prefrontal and insular cortices. Additionally, bilateral labeling was observed in several hypothalamic nuclei including the paraventricular nucleus, the dorsomedial nucleus and the ventromedial nucleus as well as the region lateral to the descending column of the fornix. Sparse labeling was also seen in various basal forebrain regions, thalamic nuclei and amygdaloid nuclei. Many of these regions were also labeled following injections in the ACe. Although double-labeled cells were never observed, afferents to the ACe were often proximal to PAG afferents. Implications of these findings are discussed in terms of two functionally distinct behavioral/cardiovascular response patterns.

Marital stress worsens prognosis in women with coronary heart disease: The Stockholm Female Coronary Risk Study

CONTEXT

Psychosocial stress has been associated with incidence of coronary heart disease (CHD) in men, but the prognostic impact of such stress rarely has been studied in women.

OBJECTIVE

To investigate the prognostic impact of psychosocial work stress and marital stress among women with CHD.

DESIGN AND SETTING

Population-based, prospective follow-up study conducted in the city of Stockholm, Sweden.

PARTICIPANTS

A total of 292 consecutive female patients aged 30 to 65 years (n = 279 working or cohabiting with a male partner) who were hospitalized for acute myocardial infarction or unstable angina pectoris between February 1991 and February 1994. Patients were followed up from the date of clinical examination until August 1997 (median, 4.8 years).

MAIN OUTCOME MEASURES

Recurrent coronary events, including cardiac death, acute myocardial infarction, and revascularization procedures, by marital stress (assessed using the Stockholm Marital Stress Scale, a structured interview) and by work stress (assessed using the ratio of work demand to work control).

RESULTS

Among women who were married or cohabiting with a male partner (n = 187), marital stress was associated with a 2.9-fold (95% confidence interval [CI], 1.3-6. 5) increased risk of recurrent events after adjustment for age, estrogen status, education level, smoking, diagnosis at index event, diabetes mellitus, systolic blood pressure, smoking, triglyceride level, high-density lipoprotein cholesterol level, and left ventricular dysfunction. Among working women (n = 200), work stress did not significantly predict recurrent coronary events (hazard ratio, 1.6; 95% CI, 0.8-3.3).

CONCLUSIONS

Our results indicate that marital stress but not work stress predicts poor prognosis in women aged 30 to 65 years with CHD. These findings differ from previous findings in men and suggest that specific preventive measures be tailored to the needs of women with CHD.

Reductions in herpes simplex virus type 2 antibody titers after cognitive behavioral stress management and relationships with neuroendocrine function, relaxation skills, and social support in HIV-positive men

OBJECTIVE

Coinfection with herpes simplex virus type 2 (HSV-2) is common in individuals infected with human immunodeficiency virus (HIV) and may have health implications. This study examined the effect of a 10-week cognitive behavioral stress management (CBSM) intervention on immunoglobulin G (IgG) antibody titers to HSV-2 in a group of mildly symptomatic HIV-infected gay men and the degree to which these effects were mediated by psychosocial and endocrine changes during the 10-week period.

METHODS

Sixty-two HIV+ gay men were randomly assigned to either a 10-week CBSM intervention (N = 41) or a wait-list control condition (N = 21). Anxious mood, social support, cortisol/dehydroepiandrosterone sulfate (DHEA-S) ratio levels, and HSV-2 IgG antibody titers were assessed at baseline and after the 10-week period. CBSM participants also recorded their stress levels before and after at-home relaxation practice.

RESULTS

HSV-2 IgG titers were significantly reduced in the CBSM participants but remained unchanged in the control group after the 10-week intervention period. Increases in one type of social support, perceived receipt of guidance, during the 10 weeks was associated with and partially mediated the effect of the intervention on HSV-2 IgG. Similarly, decreases in cortisol/DHEA-S ratio levels were associated with decreases in HSV-2 IgG, and lower mean stress levels achieved after home relaxation practice were associated with greater decreases in HSV-2 IgG among CBSM participants.

CONCLUSIONS

These findings suggest that behavioral and psychosocial changes occurring during CBSM interventions, including relaxation, enhanced social support, and adrenal hormone reductions, may help to explain the effects of this form of stress management on immune indices such as HSV-2 antibody titers.

Enhancing adherence to combination antiretroviral therapy in non-adherent HIV-positive men

This paper describes a preliminary study aimed at testing the efficacy of a brief medication counselling and behavioural intervention in improving adherence to combination antiretroviral medication therapy and prophylactic treatment among non-adherent men living with HIV. Twenty-one non-adherent HIV-positive men obtaining primary care clinical services at a Veterans Affairs Medical Center were recruited by health care providers. Intervention participants were primarily African-Americans with histories of intravenous drug use. During a period of five months, participants were provided with monthly medication counselling and a weekly medication pill organizer. Participants were compared with 21 non-adherent matched controls receiving standard pharmacy care including review of medications. Intervention and control subjects were compared on several variables: medication refill timeliness, appointment attendance, hospitalizations and opportunistic infections. Medical information was obtained from hospital and pharmacy records at baseline and post-intervention. Pre- to post-intervention rates of adherence to medication refills and clinic appointments increased significantly among intervention participants. Relative to matched controls, intervention participants also significantly increased drop-in visits and showed fewer hospitalizations. Intervention participants also showed significant decreases in the number of opportunistic infections. Results suggest that exposure to medication counselling and behavioural interventions increase adherence, with associated reductions in negative clinical outcomes.

Update in internal medicine

More than 500,000 new medical articles are published every year and available time to keep updated is scarcer every day. Nowadays, the task of selecting useful, consistent, and relevant information for clinicians is a priority in many major medical journals. This review has the aim of gathering the results of the most important findings in clinical medicine in the last few years. It is focused on results from randomized clinical trials and well-designed observational research. Findings were included preferentially if they showed solid results, and we avoided as much as possible including only preliminary data, or results that included only non-clinical outcomes. Some of the most relevant findings reported here include the significant benefit of statins in patients with coronary artery disease even with mean cholesterol level. It also provides a substantial review of the most significant trials assessing the effectiveness of IIb/IIIa receptor blockers. In gastroenterology many advances have been made in the H. pylori eradication, and the finding that the cure of H. pylori infection may be followed by gastroesophageal reflux disease. Some new antivirals have shown encouraging results in patients with chronic hepatitis. In the infectious disease arena, the late breaking trials in anti-retroviral disease are discussed, as well as the new trends regarding antibiotic resistance. This review approaches also the role of leukotriene modifiers in the treatment of asthma and discusses the benefit of using methylprednisolone in patients with adult respiratory distress syndrome, among many other advances in internal medicine.

Reductions in salivary cortisol are associated with mood improvement during relaxation training among HIV-seropositive men

This study examined salivary cortisol and mood during relaxation training in 30 symptomatic, HIV+ gay men participating in a 10-week, group-based cognitive-behavioral stress management intervention. Cortisol levels and mood were assessed within these sessions just before and after 45-min relaxation exercises given as part of each session. Participants also recorded their stress level and compliance with daily home relaxation practice. Presession cortisol levels decreased across the 10-week period and were related to decreases in global measures of total mood disturbance and anxious mood. Reductions in presession cortisol levels were also associated with decreases in self-reported stress level during home practice. Greater reductions in cortisol during the first three sessions were associated with more frequent relaxation practice at home. These findings suggest that salivary cortisol represents an objective neuroendocrine marker for changes in anxiety and distress observed during relaxation training in symptomatic, HIV-seropositive men.

Cognitive-behavioral stress management increases free testosterone and decreases psychological distress in HIV-seropositive men

The effects of a 10-week group-based cognitive-behavioral stress management (CBSM) intervention on psychological distress and plasma free testosterone in symptomatic, HIV-seropositive men were examined. Participants were randomized to either CBSM (n = 42) or a wait-list control group (n = 23). Men in the CBSM intervention showed significant increases in testosterone, whereas control participants showed significant decreases. Those participating in CBSM had significant distress reductions, whereas controls showed no such change. Alterations in free testosterone were inversely related to changes in distress states over time, independent of any changes in cortisol. These findings demonstrate that a short-term CBSM intervention increases free testosterone levels among symptomatic, HIV-seropositive men, and alterations in free testosterone are associated with changes in psychological distress observed during CBSM.

Validation of the insulin sensitivity index (ISI(0,120)): 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.

Cognitive-behavioral stress management intervention effects on anxiety, 24-hr urinary norepinephrine output, and T-cytotoxic/suppressor cells over time among symptomatic HIV-infected gay men

The present study tested the effects of a multimodal cognitive-behavioral stress management (CBSM) intervention on anxious mood, perceived stress, 24-hr urinary catecholamine levels, and changes in T-lymphocyte subpopulations over time in symptomatic HIV+ gay men. Seventy-three men were randomized to either a group-based CBSM intervention (n = 47) or a wait-list control (WLC) condition (n = 26). Men assigned to CBSM showed significantly lower posttreatment levels of self-reported anxiety, anger, total mood disturbance, and perceived stress and less norepinephrine (NE) output as compared with men in the WLC group. At the individual level, anxiety decreases paralleled NE reductions. Significantly greater numbers of T-cytotoxic/suppressor (CD3+CD8+) lymphocytes were found 6 to 12 months later in those assigned to CBSM. Moreover, greater decreases in NE output and a greater frequency of relaxation home practice during the 10-week CBSM intervention period predicted higher CD3+CD8+ cell counts at follow-up.

Cognitive-behavioral stress management increases free testosterone and decreases psychological distress in HIV-seropositive men

The effects of a 10-week group-based cognitive-behavioral stress management (CBSM) intervention on psychological distress and plasma free testosterone in symptomatic, HIV-seropositive men were examined. Participants were randomized to either CBSM (n = 42) or a wait-list control group (n = 23). Men in the CBSM intervention showed significant increases in testosterone, whereas control participants showed significant decreases. Those participating in CBSM had significant distress reductions, whereas controls showed no such change. Alterations in free testosterone were inversely related to changes in distress states over time, independent of any changes in cortisol. These findings demonstrate that a short-term CBSM intervention increases free testosterone levels among symptomatic, HIV-seropositive men, and alterations in free testosterone are associated with changes in psychological distress observed during CBSM.

Effects of combined postischemic hypothermia and delayed N-tert-butyl-alpha-pheylnitrone (PBN) administration on histopathologicaland behavioral deficits associated with transient global ischemia in rats

Previous cerebral ischemia studies have reported the limitations of restricted periods of postischemic hypothermia in producing long-term neuroprotection. The present experiment attempts to determine whether delayed treatment with the free radical scavenger N-tert-butyl-a-phenylnitrone (PBN) is protective at 2 months following transient global forebrain ischemia, and whether additive effects can be observed when PBN is administered in combination with moderate hypothermia. For this aim rats were subjected to 10 min of two-vessel forebrain ischemia followed by (a) 3 h of postischemic normothermia (37 degrees C); (b) 3 h of postischemic hypothermia (30 degrees C); (c) normothermic procedures combined with delayed injections of PBN (100 mg/kg) on days 3, 5 and 7 post-insult; (d) postischemic hypothermia combined with delayed PBN treatment; or (e) sham procedures. Outcome measures included cognitive behavioral testing and quantitative histopathological analysis at 2 months. Postischemic PBN injections induced a systemic hypothermia (1.5 degrees C-2.0 degrees C) that lasted for 2-2.5 h. Water maze testing revealed significant performance deficits relative to shams in the normothermic ischemic group, with the postischemic hypothermia and PBN groups showing intermediate values. A significant attenuation of cognitive deficits was observed in the animal group receiving the combination postischemic hypothermia and delayed PBN treatment. Quantitative CA1 hippocampal cell counts indicated that each of the ischemia groups exhibited significantly fewer viable CA1 neurons compared to sham controls. However, in rats receiving either delayed PBN treatment or 3 h of postischemic hypothermia, significant sparing of CA1 neurons relative to the normothermic ischemia group was observed. These data indicate that hypothermia combined with PBN treatment provides long-term cognitive improvement compared to nontreatment groups. PBN-induced mild hypothermia could contribute to the neuroprotective effects of this pharmacological strategy.

Ethnic variations in the pharmacological and nonpharmacological treatment of hypertension: biopsychosocial perspective

Blood pressure regulation is a complex, dynamic process influenced by psychosocial, behavioral, and cultural factors. Integrative theories of cross-population differences in the prevalence of hypertension and response to treatment include physiological, social, and genetic perspectives. Ethnic differences in salt sensitivity, calcium regulation of sodium flux, vascular reactivity to psychosocial stress, and drug metabolism are integral components of observed cross-cultural variations in hypertension. In general, pharmacological treatment of hypertension in blacks is most consistently achieved through diuretics and calcium-channel blockers; angiotensin-converting enzyme inhibitors and beta-blockers are more efficacious in whites. These stereotypical patterns are consistent with the higher prevalence of salt sensitivity, stress-induced vasoconstriction and slower natriuresis, and alpha-adrenergic receptor mediated vascular reactivity observed in blacks compared with whites. Some antihypertensive agents produce adverse glucose metabolic side effects, thus contraindicating their use in individuals with high sympathetic tone, insulin resistance, or obesity. Cross-population differences in adopted guidelines for treating hypertension exist but are not likely a factor in observed ethnic differences in rate of treatment or control. Attitudes toward nontraditional treatment options (e.g., herbal medicine), political and individual responsibilities in health care, and adaptations to acculturation and urbanization stress differ between and within societies and thus play a role in observed cross-cultural differences in hypertension as well. The value of regular exercise in controlling hypertension is widely recognized, and reductions in blood pressure reactivity to behavioral stress following acute exercise have been documented; however, empirical studies of ethnic differences in exercise-related blood pressure control are lacking. Overall, increased awareness of the multifactorial nature of hypertension by both the physician and the patient will facilitate treatment of this disease on an individual basis.

Cognitive-behavioral stress management buffers decreases in dehydroepiandrosterone sulfate (DHEA-S) and increases in the cortisol/DHEA-S ratio and reduces mood disturbance and perceived stress among HIV-seropositive men

This study examined the effects of a 10-week cognitive-behavioral stress management (CBSM) intervention on dehydroepiandrosterone sulfate (DHEA-S) levels and the ratio of cortisol to DHEA-S (cortisol/DHEA-S), potential surrogate adrenal markers of HIV disease progression, in relation to alterations in mood and distress. HIV-seropositive men were randomized to either a group-based CBSM intervention (n = 43) or to a wait-list control group (n = 24), with both hormonal and distress measures assessed just prior to and immediately following the 10-week period. Results showed that CBSM buffers decreases in DHEA-S and increases in the cortisol/DHEA-S ratio. Further examination also revealed that changes in the cortisol/DHEA-S ratio were significantly and positively related to changes in total mood disturbance and perceived stress over time. These findings demonstrate that a short-term CBSM intervention can buffer against decrements in DHEA-S and increments in the cortisol/DHEA-S ratio among symptomatic, HIV-positive men, and that alterations in the cortisol/DHEA-S ratio move in concert with changes in mood and distress observed during CBSM.

Cardiopulmonary and CD4 cell changes in response to exercise training in early symptomatic HIV infection

PURPOSE

The purposes of the present study were to assess the effects of a 12-wk laboratory based aerobic exercise program on cardiopulmonary function, CD4 cell count, and physician-assessed health status among symptomatic pre-AIDS HIV-infected individuals (N = 28) and to assess the degree to which ill health was associated with exercise relapse.

METHODS

Responses to graded exercise test, physician-assessed health status, and CD4 cell counts were determined at baseline and 12-wk follow-up for participants randomly assigned to exercise or control conditions, and reasons for exercise noncompliance were recorded.

RESULTS

Approximately 61% of exercise-assigned participants complied (> 50% attendance) with the exercise program, and analyses of exercise relapse data indicated that obesity and smoking status, but not exercise-associated illness, differentiated compliant from noncompliant exercisers. Compliant exercisers significantly improved peak oxygen consumption (VO2peak; 12%), oxygen pulse (O2pulse; 13%), tidal volume (TV; 8%), ventilation (VE; 17%), and leg power (25%) to a greater degree than control participants and noncompliant exercisers (all P < 0.05). Although no group differences in health status were found, a significant interaction effect indicated that noncompliant exercisers' CD4 cells declined (18%) significantly, whereas compliant exercisers' cell counts significantly increased (13%; P < 0.05).

CONCLUSION

We conclude that although aerobic exercise can improve cardiopulmonary functioning in symptomatic HIV-infected individuals with minimal health risks, attention to factors associated with exercise adherence is warranted.

History of gestational diabetes, insulin resistance and coronary risk

The purpose of this study was to examine characteristics associated with the insulin metabolic syndrome, including insulin resistance, abnormal glucose tolerance, dyslipidemia, obesity, and elevated blood pressure, among women who have experienced gestational diabetes. 39 nondiabetic, young (20-42 years), postpartum (3-18 months) white women were recruited from obstetrical clinics. Twenty-one women had a history of gestational diabetes; 18 had uncomplicated pregnancies. Multivariate analyses revealed a significant difference between groups in insulin resistance (M, measured by euglycemic clamp) and insulin levels (from an oral glucose tolerance test), with insulin resistance showing a statistically stronger difference than insulin levels. Groups also differed significantly when compared on a set of variables associated with insulin metabolic syndrome: glucose tolerance, triglycerides, blood pressure, and body-mass index. Using insulin resistance as a covariate eliminated these group differences, suggesting that insulin resistance is the key factor underlying insulin metabolic syndrome. The higher risk of later developing type 2 diabetes and hypertension in women who have a history of gestational diabetes is explicable by their poorer profile on variables associated with insulin metabolic syndrome, and appears to be attributable to insulin resistance. Thus, insulin resistance appears to distinguish young women at risk for cardiovascular disease.

Is fasting leptin associated with insulin resistance among nondiabetic individuals? The Miami Community Health Study

OBJECTIVE

Whether serum leptin levels are associated with insulin resistance independent of the effects of hyperinsulinemia and adiposity is an important unanswered question. We examined the relationship between the rate of insulin-mediated glucose uptake and serum leptin concentrations among nondiabetic men and women.

RESEARCH DESIGN AND METHODS

A cross-sectional analysis was performed among 49 young to middle-aged men and women who participated in the Miami Community Health Study. All participants had measures of insulin resistance (euglycemic-hyperinsulinemic clamp), postchallenge insulin levels, fasting serum leptin levels, and several measures of adiposity.

RESULTS

The rate of insulin-mediated glucose uptake (M in milligrams per kilogram per minute) was significantly associated with leptin concentrations in both men (r = -0.83; P < 0.001) and women (r = -0.59; P < 0.001). M was also inversely related to percent body fat and to the 2-h insulin area under the curve (AUC). After covariate adjustment for sex, percent body fat, and AUC, leptin remained a significant correlate of M (P = 0.04).

CONCLUSIONS

Cross-sectionally, leptin was significantly associated with insulin resistance in this nondiabetic sample of men and women. There may be a different physiological mechanism to explain the leptin/insulin resistance association apart from the insulin/adiposity link. Confirmatory evidence awaits the results of clinical trials.

Behavioral medicine and the management of HIV/AIDS

Psychosocial treatment studies provide a method for conducting causal investigations within a clinical environment. They can also inform about relations between psychosocial or biobehavioral processes on the one hand, and disease on the other. Our studies conducted on HIV-positive (HIV+) homosexual men indicate that a group-based cognitive behavioral stress management (CBSM) intervention can decrease distress, buffer the psychological and immunological sequelae of HIV+ serostatus notification, and improve surveillance of herpes viruses. Decreased dysphoria induced by CBSM appears to be a significant mediator of control over cellular immunity. Poor HIV+ African American women, as well as more affluent gay men, benefit from group-based CBSM, but important gender and sociocultural differences must be taken into account in developing protocols. Adherence to highly active antiretroviral therapy (HAART), coupled with good health behavior, can contain HIV/AIDS in most instances. In contrast, poor HAART adherence coupled with poor health behavior (e.g., unprotected sex) can lead to drug resistance and infection of partners with virulent mutated strains. Thus, now more than ever, behavioral medicine approaches to management and secondary prevention of HIV/AIDS are needed.

Cognitive-behavioral intervention effects on mood and cortisol during exercise training

The purpose of the present study was to assess the effect of a time limited cognitive-behavioral stress management program (CBSM) on mood state and serum cortisol among men and women rowers (N = 34) undergoing a period of heavy exercise training. After controlling for life-event stress (LES), CBSM was hypothesized to reduce negative mood state and cortisol among rowers during a period of heavy training; mood and cortisol changes over the intervention period were hypothesized to be positively correlated. LES was positively associated with negative affect at study entry. After covariance for LES, rowing athletes randomly assigned to the CBSM group experienced significant reductions in depressed mood, fatigue, and cortisol when compared to those randomized to a control group. Decreases in negative affect and fatigue were also significantly associated with cortisol decrease. These results suggest that CBSM may exert a positive effect on athletes' adaptation to heavy exercise training.

Cigarette smoking, alcohol use, and physical activity in relation to serum leptin levels in a multiethnic population: The Miami Community Health Study

PURPOSE

To examine the correlates of plasma leptin, including fasting insulin, adiposity, and several health habits and behaviors among a nondiabetic multiethnic population.

METHODS

A cross-sectional study was conducted among 25-44 year old African-Americans (n = 126), Cuban-Americans (n = 107), and non-Hispanic whites (n = 189) randomly selected from Dade County Florida. Fasting leptin levels were correlated with fasting insulin, percent body fat, smoking, alcohol use, and physical activity within each sex. Multiple linear regression and analysis of covariance were used to estimate the independent determinants of plasma leptin concentration separately among men and women.

RESULTS

Stepwise linear regression analyses revealed statistically significant associations of leptin with percent body fat, fasting insulin, cigarette smoking, and physical activity (both inversely) among men (p < 0.05 for each). Among women, percent body fat, fasting insulin (both positively), cigarette smoking, and alcohol use (inversely) were independent predictors of leptin levels explaining over 70% of the variance. Analyses of covariance revealed that women had higher adjusted mean leptin levels than men (13.1 ng/ml vs. 5.9 ng/ml; p < 0.001), whereas no separate effect of ethnicity was noted.

CONCLUSIONS

Although adiposity was the strongest correlate of leptin levels, fasting insulin and several health habits and behaviors were independently associated with leptin. After adjustment for these factors, women had significantly higher mean leptin levels than men. The independent association among leptin and insulin levels is intriguing and suggests additional avenues for epidemiologic research.

Contribution of NMDA and non-NMDA receptors to synaptic transmission from the brachium of the inferior colliculus to the medial subdivision of the medial geniculate nucleus in the rabbit

Previous work from this laboratory has demonstrated that monosynaptic inputs from the brachium of the inferior colliculus (BIC) to the medial subdivision of the medial geniculate nucleus (mMG) strengthen as a result of associative conditioning with an acoustic conditioned stimulus (i.e., fear conditioning). One model that has been proposed to underlie certain types of neuronal plasticity involves the recruitment of N-methyl-D-aspartic acid (NMDA)-type glutamate receptors. The purpose of the present study was to examine the relative contributions of glutamatergic NMDA and non-NMDA receptors to synaptic transmission within this pathway. Individual contributions of the specific receptor types were assessed through the use of 2-amino-5-phosphonovaleric acid (AP5), a selective NMDA receptor antagonist, and 6-cyano-5-nitroquinoxaline-2,3-dione (CNQX), a non-NMDA receptor antagonist. Bipolar stimulating electrodes were stereotaxically implanted in BIC and recording electrodes (attached to dual 32-gauge cannulae for delivery of drug) were positioned in mMG of New Zealand albino rabbits. Single pulses (150 micros, 100-350 microA) delivered to BIC resulted in short-latency (<4 ms) responses in mMG. BIC-evoked single-unit activity was recorded from mMG before, during, and at several intervals after injection of AP5, CNQX, and/or artificial cerebrospinal fluid (ACSF). Injection of either AP5 or CNQX, but not ACSF, significantly attenuated the short-latency BIC-evoked responses in the vast majority of cells tested. These findings suggest that the monosynaptic pathway from BIC to mMG is glutamatergic and that this pathway frequently employs NMDA-type receptors during electrically stimulated synaptic transmission. Due to the NMDA receptors' proposed role in plasticity (e.g., long-term potentiation), these results may have implications for understanding the mechanisms of synaptic plasticity observed at this synapse during associative learning.

Classification of individual differences in cardiovascular responsivity: The contribution of reactor type controlling for race and gender

Classification of 150 normotensive or mildly hypertensive men and women into myocardial, vascular, or mild reactors was accomplished using a regression-based approach. The method was based on the participants' cardiac output (CO) and total peripheral resistance (TPR) reactivity to the speech presentation task. This task purportedly can elicit both myocardial and vascular responses. Cut-scores were based on the y-intercept from the linear regression of the CO reactivity on TPR reactivity and vice versa. A greater percentage of Black men were classified as vascular responders as compared to Black women and White participants. Groups were found to differ on cardiovascular reactivity to the speech preparation, cold pressor, and mirror tracing tasks in predictable ways, after controlling for gender and ethnicity. Groups were also differentiated by ambulatory blood pressure and hypertensive status. The study supports the classification of homogenous groups of participants based on the relative extent to which myocardial or vascular mechanisms dominate the reactivity to stress.

Cardiovascular and perceptual effects of reporting pain during the foot and forehead cold pressor tests

In research involving the cold pressor test, a tacit presumption is often made that reporting pain during stimulation is not in itself reactive. This study examined whether, for the foot and forehead cold pressor tests, activities involved in reporting pain may affect (a) the evoked pattern of cardiovascular response, and (b) the magnitude of self-perceived pain. In 40 normotensive college men, increases in systolic blood pressure were greater during test sessions that included verbal ratings of pain, as compared to sessions in which pain was not reported. In contrast to its effect on physiological activation, reporting pain did not significantly alter the participant's perception of the painfulness of the lest, on recollection shortly after the test. We conclude, therefore, that reporting pain during the cold pressor test may impose significant additional demands on the cardiovascular system, but it does not interfere significantly with the processing of nociceptive information.

The relation of fasting insulin to blood pressure in a multiethnic population: the Miami Community Health Study

PURPOSE

The aim of this study was to examine the associations among fasting insulin, adiposity, waist girth, and blood pressure among a nondiabetic multiethnic population.

METHODS

A cross-sectional study was performed among 25-44-year-old African-Americans (n = 159), Cuban-Americans (n = 128), and non-Hispanic whites (n = 207) selected from Dade County, Florida. Fasting insulin levels were correlated with resting blood pressure level within each ethnic group. The separate effects of percentage body fat and waist girth on the association between blood pressure and insulin were analyzed in multiple linear regression and analysis of covariance.

RESULTS

Fasting insulin was positively associated with systolic (r = 0.26-0.39; P < 0.01) and diastolic blood pressure (r = 0.19-0.30; P = 0.10 to P < 0.001) among women of all ethnic groups and among non-Hispanic white men (r = 0.27; P < 0.05). Stepwise linear regression analyses revealed statistically significant associations between systolic and diastolic blood pressure and fasting insulin level in non-Hispanic whites independent of other covariates, including sex and percentage body fat (P < 0.001). Fasting insulin was also independently and significantly related to systolic blood pressure among African-Americans (P = 0.02). Among Cuban-Americans, sex and percentage body fat were the main correlates of blood pressure level. Analysis of covariance revealed a relationship between insulin and blood pressure that was independent of waist girth among men and women.

CONCLUSIONS

Fasting insulin level and blood pressure were positively associated among African-Americans and non-Hispanic whites. This association was not entirely due to the common association with percentage body fat or waist girth.