Frank A. Treiber

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.

Evaluation of a brief telephone questionnaire to estimate fruit and vegetable consumption in diverse study populations

We evaluated use of a six-item telephone questionnaire to estimate fruit and vegetable intakes in five diverse populations. Researchers administered the telephone questionnaire to persons who had previously undergone more extensive dietary assessment. The study populations included 553 middle-aged and older adults in Beaver Dam, WI; 252 middle-aged and older women throughout Wisconsin; 150 parents of school children in Augusta, GA; 73 low-income, Hispanic mothers in Chicago, IL; and 51 older adults in Arizona. Spearman correlation coefficients between total fruit and vegetable intakes measured by the brief telephone survey and by more extensive food frequency questionnaires were 0.47 (Augusta), 0.48 (Arizona), 0.56 (Wisconsin), and 0.57 (Beaver Dam). Correlation between intakes measured by the brief telephone survey and by multiple diet records or recalls were 0.29 (Arizona), 0.46 (Chicago), and 0.54 (Beaver Dam). With the exception of Arizona, mean daily fruit and vegetable intakes measured by the telephone survey were similar to intakes estimated by multiple diet records or recalls and lower than those estimated by extensive food frequency questionnaires. Although caution may be needed in interpreting dietary reports from some ethnic subgroups, this brief telephone questionnaire may be useful for surveillance of fruit and vegetable intake in the United States. (Epidemiology 1993;4:455–463)

Impact of Transcendental Meditation on cardiovascular function at rest and during acute stress in adolescents with high normal blood pressure.

OBJECTIVE This study examined the impact of the Transcendental Meditation (TM) program on cardiovascular (CV) reactivity in adolescents with high normal BP. METHOD Thirty-five adolescents [34 African Americans (AAs), 1 Caucasian American (CA); ages 15-18 years] with resting systolic blood pressure (SBP) between the 85th and 95th percentile for their age and gender on three consecutive occasions, were randomly assigned to either TM (n=17) or health education control (CTL, n=18) groups. The TM group engaged in 15-min meditation twice each day for 2 months including sessions during school lunch break. Primary CV outcome measures were changes in blood pressure (BP), heart rate (HR), and cardiac output (CO) at rest and in response to two laboratory stressors, a simulated car driving stressor and an interpersonal social stressor interview. RESULTS The TM group exhibited greater decreases in resting SBP (P<.03) from pre- to postintervention, compared to the CTL group. The TM group exhibited greater decreases from pre- to postintervention in SBP, HR, and CO reactivity (Ps<.03) to the simulated car driving stressor, and in SBP reactivity (P<.03) to the social stressor interview. CONCLUSION The TM program appears to have a beneficial impact upon CV functioning at rest and during acute laboratory stress in adolescents at-risk for hypertension.

Anger and hostility in depression.

The present study examined the relationship between depression and various dimensions of anger using multiple measures of anger and hostility and comparing depressed subjects with both a normal sample and a clinical sample with predominant anger difficulties. Three groups of subjects were obtained: a normal sample of 120 parents of elementary school children, 36 psychiatric inpatients meeting Research Diagnostic Criteria for major depressive episode, and 54 hospitalized veterans meeting Diagnostic Interview Schedule criteria for posttraumatic stress disorder (PTSD). The three groups differed significantly on all measures of anger experience, hostility, anger suppression, and anger expression. The depressed group reported greater levels of hostility and anger experience than the normal group but less than the PTSD group. On measures of anger suppression and expression, the depressed group exhibited more suppression than either the normal or the PTSD group and generally reported levels of anger expression comparable with the normal groups. The PTSD group reported the highest levels of anger expression. Within the depressed group, severity of depression was positively associated with levels of hostility and anger experience but was not related to measures of anger expression and was only partially related to anger suppression. These results are discussed as they relate to the “anger turned in” hypothesis of psychodynamic theories of depression, and directions for future research are noted.

Obesity related methylation changes in DNA of peripheral blood leukocytes

BackgroundDespite evidence linking obesity to impaired immune function, little is known about the specific mechanisms. Because of emerging evidence that immune responses are epigenetically regulated, we hypothesized that DNA methylation changes are involved in obesity induced immune dysfunction and aimed to identify these changes.MethodWe conducted a genome wide methylation analysis on seven obese cases and seven lean controls aged 14 to 18 years from extreme ends of the obesity distribution and performed further validation of six CpG sites from six genes in 46 obese cases and 46 lean controls aged 14 to 30 years.ResultsIn comparison with the lean controls, we observed one CpG site in the UBASH3A gene showing higher methylation levels and one CpG site in the TRIM3 gene showing lower methylation levels in the obese cases in both the genome wide step (P = 5 × 10-6 and P = 2 × 10-5 for the UBASH3A and the TRIM3 gene respectively) and the validation step (P = 0.008 and P = 0.001 for the UBASH3A and the TRIM3 gene respectively).ConclusionsOur results provide evidence that obesity is associated with methylation changes in blood leukocyte DNA. Further studies are warranted to determine the causal direction of this relationship as well as whether such methylation changes can lead to immune dysfunction.See commentary: http://www.biomedcentral.com/1741-7015/8/88/abstract

Increasing fruit and vegetable consumption among 4th and 5th grade students: results from focus groups using reciprocal determinism

Abstract The Year 2000 Goals for the U.S. identify a goal of five servings per day of fruits and vegetables (F&V), which is roughly double what children are currently eating. Focus group discussions (based on the reciprocal determinism concept in social learning theory) were conducted with 4th and 5th grade students, their parents, teachers, and school food service workers, in preparation for the design of a school nutrition education program to increase consumption of F&V. A social learning theory perspective was taken because it has been demonstrated to be useful in the design of effective school nutrition education programs. A theory-based protocol delineating the sequence of questions to be asked in each focus group was designed before each group met. Discussions were conducted with ten groups of students, two groups each of teachers and of parents, and one of school food service employees. Three general factors appeared to be most likely to increase F&V consumption in these children: increasing availability of F&V in the home, enhancing liking for vegetables, and providing skills in increasing F&V availability and in preparing F&V.

Ethnic and Gender Differences in Ambulatory Blood Pressure Trajectories Results From a 15-Year Longitudinal Study in Youth and Young Adults

Background— Cross-sectional studies demonstrated ethnic and gender differences in ambulatory blood pressure patterns, but little is known about the longitudinal development of these differences. Methods and Results— Twenty-four-hour ambulatory blood pressure was measured up to 12 times (5 times on average) over a 15-year period in 312 African Americans (AAs) and 351 European Americans aged 7 to 30 years. Multivariate individual growth curves across age were created for daytime and nighttime blood pressure jointly. For both daytime and nighttime systolic blood pressure (SBP), AAs and males had higher levels (P<0.001) than European Americans and females. Males also showed a greater increase with age (P<0.001) than females. For nighttime SBP, a faster increase of SBP with age (P<0.01) in AAs was additionally observed. The ethnic difference in nighttime SBP levels and its increase with age were significantly larger than in daytime SBP. For daytime and nighttime diastolic blood pressure, AAs had higher levels than European Americans (P<0.001), and this difference was significantly larger at night. From late adolescence onward, males showed a greater increase in diastolic blood pressure with age than females. Ethnic and gender differences persisted after adjustment for height, body mass index, socioeconomic status, and stress-related coping styles. Family history of essential hypertension explained ethnic differences in daytime SBP. Conclusions— We observed significant ethnic and gender differences in longitudinal trajectories of ambulatory blood pressure in youth and young adults. The blunted nocturnal decline and its exacerbation with age in AAs corroborate and extend findings of cross-sectional studies.

Heritability of Blood Pressure and Hemodynamics in African- and European-American Youth

Abstract— Hypertension prevalence is much higher in African‐Americans (AAs) than in European‐Americans (EAs). It is unknown whether this difference is related to potential ethnic differences in the relative contribution of genes and environment to population variation in blood pressure and underlying hemodynamics. We studied 308 EA and 226 AA twin pairs, including monozygotic and dizygotic twins, of the same as well as the opposite sex (mean±SD age, 14.7±3.1 years). Supine resting systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure, and heart rate (HR) were measured by a Dinamap instrument and hemodynamics (stroke volume, cardiac index, and total peripheral resistance [TPR] index) by impedance cardiography. Ethnic and sex effects on genetic and environmental contributions to resting blood pressure and hemodynamics were estimated by genetic model fitting. For most measures, the best‐fitting model showed no differences in heritability between AAs and EAs or between males and females, with heritabilities of 0.50 for cardiac index, of 0.64 for HR, and of SBP, pulse pressure, and stroke volume in between. Heritability of DBP was 0.45 in EAs and 0.58 in AAs with no effect of sex. For TPR index in EAs, 46% of the variance could be attributed to familial effects, but no significant distinction could be made between shared environmental and genetic factors. Heritability of TPR index in AAs was 0.51. Adjustment for obesity yielded virtually identical heritabilities. In summary, relative influences of genetic and environmental factors on blood pressure and hemodynamics in AA and EA youth are similar and independent of (genes for) obesity.

Impact of meditation on resting and ambulatory blood pressure and heart rate in youth.

Objective: The purpose of this study was to evaluate the impact of a meditation program on resting and ambulatory blood pressure and heart rate in youth. Methods: Data from 73 middle school students (age 12.3 ± 0.6 years) randomly assigned by classroom to either meditation (N = 34) or health education control (N = 39) groups were analyzed. The meditation groups engaged in 10-minute sessions at school and at home after school each day for 3 months. Resting (seated) systolic blood pressure, diastolic blood pressure, and heart rate measurements were obtained pretest and posttest on three consecutive school days using Dinamap 1846SX monitors. Ambulatory systolic blood pressure, ambulatory diastolic blood pressure, and ambulatory heart rate were recorded over 24-hour periods at pretest and posttest every 20 minutes during self-reported normal waking hours and every 30 minutes during self-reported normal sleep hours using Spacelabs 90207 monitors. Results: Significant (p < .05) differences in average change from pretest to posttest were found between the meditation and health eduction control groups for resting systolic blood pressure (−2.7 vs. 1.1 mm Hg), daytime ambulatory systolic blood pressure after school (−2.0 vs. 3.6 mm Hg), daytime ambulatory diastolic blood pressure after school (0.1 vs. 4.3 mm Hg), and daytime ambulatory heart rate after school (−5.3 vs. 0.3 bpm). Conclusion: These findings demonstrate the potential beneficial impact of meditation on blood pressure and heart rate in the natural environment in healthy normotensive youth. AA = African American; ABP = ambulatory BP; ANOVA = analysis of variance; BP = blood pressure; bpm = beats per minute; CA = Caucasian; CTL = health education control; CVD = cardiovascular disease; DBP = diastolic blood pressure; EH = essential hypertension; HR = heart rate; HPA = hypothalamic-pituitary-adrenocortical; MANOVA = multivariate analysis of variance; MED = meditation; MBSR = Mindfulness-Based Stress Reduction; PMR = progressive muscle relaxation; SBP = systolic blood pressure; SNS = sympathetic nervous system; TM = Transcendental Meditation™.

Validation of a heart rate monitor with children in laboratory and field settings

The validity of the Sport Tester PE 3000 portable heart rate monitor for use with children was assessed by comparing readings with simultaneously recorded ECG heart rates in three studies, two using laboratory tasks and one in a field setting. Study 1 examined the validity of the Sport Tester with a sample of ten 10-yr-olds performing a cycle ergometer exercise task. Sport Tester readings taken during three 3-min exercise loads were correlated from 0.97 to 0.99 with simultaneously recorded ECG heart rates. In study 2, 23 children from 4 to 6 yr of age performed treadmill exercise for three 1-min intervals while Sport Tester and ECG heart rate data were obtained. Correlations for the three intervals ranged from 0.94 to 0.99. Study 3 obtained ECG and Sport Tester heart rates in 14 7- to 9-yr-olds who engaged in 3-min periods of standing, walking, jogging, throwing a ball, batting a ball, and playing on a jungle gym. Significant correlations of at least 0.98 between Sport Tester and ECG heart rates were obtained during all six activities. For all three studies, standard errors of estimate were low, ranging from 1.1 to 3.7 beats.min-1. For individuals, maximum differences ranged from 0 to 12.4 beats.min-1. Collectively, these findings indicate that the Sport Tester provides valid readings of young childrens heart rates across a wide range of exercise involving upper- and lower-body movements.