Impact of Transcendental Meditation on Left Ventricular Mass in African American Adolescents

Background. An early sign of ventricular remodeling is increased left ventricular mass (LVM) which over time may lead to left ventricular hypertrophy, the strongest predictor of cardiovascular morbidity and mortality, other than advancing age. Methods. 62 (30 TM; 32 CTL) African American adolescents (age 16.2 ± 1.3 years) with high normal systolic BP were randomly assigned to either 4-month Transcendental Meditation (TM) or health education control groups. The echocardiographic-derived measure of LVM index (LVMI = LVM/ht2.7) was measured before and after the 4-month TM study and at 4-month followup. 2D-guided M-mode echocardiography using a Hewlett Packard 5500 echosonograph was used to determine LVMI. Results. The TM group exhibited a greater decrease in LVMI at 4-month followup compared to the CTL group (−2.6 versus +0.3 gm/ht2.7, P < 0.04). The TM group exhibited a lesser increase in BMI at 4-month follow-up compared to the CTL group (0.2 ± 1.6 versus 1.1 ± 1.4, P < 0.03). Conclusion. These findings indicate that among a group of prehypertensive African American adolescents, 4 months of TM compared to heath education resulted in a significant decrease in LVMI, and these changes were maintained at 4-month follow-up

Decreased heritability and emergence of novel genetic effects on pulse wave velocity from youth to young adulthood

Increased arterial stiffness measured by pulse wave velocity (PWV) is an important parameter in the assessment of cardiovascular risk. Our previous longitudinal study has demonstrated that carotid-distal PWV showed reasonable stability throughout youth and young adulthood. This stability might be driven by genetic factors that are expressed consistently over time. We aimed to illustrate the relative contributions of genetic and environmental factors to the stability of carotid-distal PWV from youth to young adulthood. We also examined potential ethnic differences. For this purpose, carotid-distal PWV was measured twice in 497 European American (EA) and African American (AA) twins, with an average interval time of 3 years. Twin modelling on PWV showed that heritability decreased over time (62-35%), with the nonshared environmental influences becoming larger. There was no correlation between the nonshared environmental factors on PWV measured at visit 1 and visit 2, with the phenotypic tracking correlation (r=0.32) completely explained by shared genetic factors over time. Novel genetic influences were identified accounting for a significant part of the variance (19%) at the second measurement occasion. There was no evidence for ethnic differences. In summary, novel genetic effects appear during development into young adulthood and account for a considerable part of the variation in PWV. Environmental influences become larger with age for PWV

Social Media and Cardiovascular Disease

Personality subtypes and systolic blood pressure (SBP) at night are recognized predictors of cardiovascular disease among social media users. Healthy individuals (n=88, 77% female, 31% African American) were surveyed using the Media and Technology Usage and Attitudes Scale (MTUAS). Demographics, 24-hours SBP, and personality types (e.g., introvert, extravert, and blended) were used. Personality (B= 5.37, t= 2.86, p=.005) significantly predicted elevated SBP in social media users (r2= .157, F(4, 72)=3.37, p=.014). There was a significant gradient increase in nighttime SBP by personality [introvert (M=100, SD=2.1), extrovert (M=102, SD=1.7), and blended (M=111, SD=4.4); all ps.&lt;0.05]. Negative attitudes toward using technology (B= -5.093, t= -2.390, p= .019) also significantly predicted elevated overnight SBP. Higher anxiety/dependence with mobile phones (B=.400, t= 2.49, p=.019) significantly predicted elevated nighttime SBP [r2 = 0.342 F(4, 27) = 3.505, p=.020]. Our findings indicate that a blended personality type and anxiety due to separation from or dependence on a mobile phone or internet use elevate SBP at night, increasing the risk of developing cardiovascular disease

DNA Methylation of the LY86 Gene is Associated With Obesity, Insulin Resistance, and Inflammation

Background: Previous genome-wide association studies (GWAS) have identified a large number of genetic variants for obesity and its related traits, representing a group of potential key genes in the etiology of obesity. Emerging evidence suggests that epigenetics may play an important role in obesity. It has not been explored whether the GWAS-identified loci contribute to obesity through epigenetics (e.g., DNA (deoxyribonucleic acid) methylation) in addition to genetics. Method: A multi-stage cross-sectional study was designed. We did a literature search and identified 117 genes discovered by GWAS for obesity and its related traits. Then we analyzed whether the methylation levels of these genes were also associated with obesity in two genome-wide methylation panels. We examined an initial panel of seven adolescent obese cases and seven age-matched lean controls, followed by a second panel of 48 adolescent obese cases and 48 age- and gender-matched lean controls. The validated CpG sites were further replicated in two independent replication panels of youth (46 vs. 46 and 230 cases vs. 413 controls, respectively) and a general population of youth, including 703 healthy subjects. Results: One CpG site in the lymphocyte antigen 86 (LY86) gene, which showed higher methylation in the obese in both the initial (p=.009) and second genome-wide DNA methylation panel (p=.008), was further validated in both replication panels (meta p=.00016). Moreover, in the general population of youth, the methylation levels of this region were significantly correlated with adiposity indices (

Impaired vasodilation in pregnant African Americans: Preliminary evidence of potential antecedents and consequences

Significant health disparities exist between African Americans (AA) and European Americans (EA) in hypertension and hypertension-related disorders. Evidence suggests that this is due to impaired vasodilation in AAs. Pregnancy is a potent systemic vasodilatory state. However, differences in vasodilation between AAs and EAs have not been investigated in pregnancy. We sought to examine the effects of pregnancy on vasodilation in AA and EA women and how this might be related to discrimination and low birth weight in their offspring. Hemodynamics [blood pressure (MAP), cardiac output (CO), total peripheral resistance (TPR)] and heart rate variability (HF-HRV) were examined at baseline in 40 pregnant AAs (n = 20) and EAs (n = 20) and matched nonpregnant women (n = 40). The Experiences of Discrimination scale and birth weight were also measured in the offspring of the pregnant participants. Whereas pregnancy was associated with decreased MAP independent of race, AAs showed impaired vasodilation independent of pregnancy status as indicated by greater TPR despite greater HF-HRV. In AAs, but not EAs, reports of fewer incidences of discrimination were associated with greater TPR. Finally, the HF-HRV of EA mothers was inversely related to the birth weight of their offspring but was uncorrelated in AAs. We report novel evidence of impaired vasodilation to an endogenous vasodilatory stimulus in AAs. Higher TPR was related to discrimination in AAs and higher HF-HRV was related to low birth weight in EAs. These findings have implications for understanding the intergenerational transmission of impaired vasodilation in AAs

Insulin Resistance Syndrome and Left Ventricular Mass in Healthy Young People

Findings of atherosclerotic plaques in adolescents, in the context of current epidemics of obesity and type 2 diabetes in youth, demand investigation into early cardiovascular risk development. Left ventricular hypertrophy has been linked to hypertension, obesity, and insulin resistance. Insulin resistance syndrome characteristics (fasting glucose and insulin; systolic blood pressure; waist girth) were measured in 70 normotensive, normoglycemic young people (60% male, 62% black; included 13 twin pairs; age mean±SD, 19±2.6 years). Left ventricular mass indexed by height2.7 (LVMI) was obtained via ultrasound. Twin pairs were clustered to satisfy the assumption for independent observations. LVMI was regressed on insulin after controlling for race, gender, and systolic blood pressure. Insulin was a significant (P=0.02) independent predictor of LVMI (R2change=0.09, P<0.01). Waist girth accounted for an additional 4% variance of LVMI (P=0.05). A one-factor model comprising waist (factor loading=0.83), insulin (0.59), glucose (0.42), and LVMI (0.46) showed good fit [χ2(2)=0.41, P=0.81; root-mean-square error of approximation=0.0]. A subclinical metabolic syndrome is detectable early in life, before abnormal fasting glucose or high blood pressure appear. Evidence of excessive load on the heart is associated with the metabolic syndrome even after accounting for the effects of race, gender, and blood pressure. Cardiac structure seems as closely associated with this syndrome as fasting glucose level. Based on this evidence, we propose that increased left ventricular mass is a part of insulin resistance syndrome and adds to the need for preventive public health measures to improve health behaviors and cardiovascular risk status in US youth

Determinants of pulse wave velocity trajectories from youth to young adulthood: the Georgia Stress and Heart Study

Objective: Increased arterial stiffness measured by pulse wave velocity (PWV) has been shown to be an important parameter of cardiovascular risk. Longitudinal development of PWV from youth to early adulthood and its possible sociodemographic, anthropometric, hemodynamic and behavioral moderators will be illustrated. Methods: Individual growth curves of carotid-distal PWV across age were created for 559 African American and European American men and women with a maximum of five assessments over an average of 7-year follow-up (mean age at participants' first assessment, 22.3 +/- 3.4). Results: African Americans and men had significantly higher PWV than did European Americans and women (Ps<0.01), respectively. A three-way interaction (P<0.001) between age, sex and ethnicity was observed with African American men displaying a larger rate of increase in PWV with age than the other three ethnic and sex groups. The ethnicity and sex effects on PWV persisted when controlling for other moderators. Waist circumference was the strongest anthropometric predictor but its effect on PWV was only significant in women. Mean arterial pressure was the strongest hemodynamic predictor, marital status of parents was the strongest socioeconomic predictor and marijuana use was the strongest behavioral predictor of PWV. The best-fitting full model explained in total 59.4% of the between-subject variance in PWV with ethnicity, sex and age explaining 25.6%. Conclusion: We observed significant ethnic and sex differences in longitudinal trajectories of PWV in youth and young adults. In addition, individual differences in PWV growth can largely be explained by mean arterial pressure, waist, marital status of parents and marijuana use