OBJECTIVE: To examine the impact of central adiposity upon hemodynamic functioning at rest and during stress in adolescents. DESIGN: Cross-sectional, correlational study. SUBJECTS: 46 White and 49 Black normotensive adolescents with family histories of essential hypertension. MEASUREMENTS: Systolic and diastolic blood pressure (SBP, DBP), cardiac output and total peripheral resistance responses were assessed at rest, during postural change, video game challenge and forehead cold stimulation. Speci®c lower and higher waist-to-hip ratio (WHR) tertiles were created for each gender and then integrated for analyses. This resulted in a lower WHR tertile of 11 Whites and 21 Blacks and an upper WHR tertile of 15 Whites and 17 Blacks. RESULTS: No differences in age, gender or ethnicity proportions were found between tertile groups (all P b 0.21). The upper WHR group showed greater body weight, waist and hip circumferences, body mass index (BMI), triceps skinfold and body surface area (all P`0.001). Controlling for peripheral (that is, triceps skinfold) and overall (that is, BMI) adiposity, the upper WHR group exhibited greater SBP (that is, peak response minus mean pre-stressor level) to all three stressors and greater DBP reactivity to postural change and cold pressor (all P`0.05). CONCLUSION: Central adiposity appears to adversely in¯uence hemodynamic functioning during adolescence. Underlying mechanisms responsible for these associations require exploration.

Objective: Obesity is associated with multiple health problems and often originates in childhood. This study investigated the association of genes with the development of general and central obesity from childhood into adulthood. Design: Individual growth curves for measures of general adiposity were examined in an 11-year (1987-1998) cohort study. Single-nucleotide polymorphisms (SNPs) in 11 candidate genes were genotyped. Subjects: Five hundred and twenty-six subjects classified by race (49% African American (AA)), sex (47% male) and socioeconomic status (SES). Results: AA female carriers of the 27Glu allele in the ADRB2 gene had a larger waist circumference (Po0.05). Subjects of high SES with the ApoB 4145Lys allele had a larger mean waist circumference than those without this allele (Po0.05). Only in the presence of an adverse environment (low SES) did carriers of the NOS3 298Asp allele have a larger mean body mass index, waist circumference and sum of skinfolds (Po0.05). Conclusion: These results suggest that several polymorphisms are associated with the mean level of adiposity, with the effects depending on other factors such as race, sex and/or SES.

We assessed blood pressure responses of a multiethnic (Black and White) sample of 120 children of hypertensive families to orthostasis, video game, forehead cold, and dynamic exercise, and monitored the children's ambulatory pressure 24 hours later. Thirteen children were studied twice (1-year stability). The Black children exhibited higher 24-hour ambulatory systolic and diastolic pressures than the White children. Regardless of ethnicity, peak and mean systolic pressures during each task were generally positively correlated with mean systolic pressure while the children were awake and asleep. Associations between diastolic pressor responses and ambulatory measurements were somewhat dependent upon ethnicity and task. Relatively few reactivity-ambulatory correlations were significant, using pressor reactivity change scores. The children who participated twice exhibited significant 1-year stability for most ambulatory and pressor measurements. Children's pressor responses to laboratory tasks may generalize to the natural environment.

Dialysis patients are at risk of attrition from Kidney Transplant (KT) wait lists due to sedentary lifestyle and poor nutritional adherence. This study tested the acceptability of several mobile Health (mHealth) intervention components for the development of a lifestyle program to support kidney wait-list patients. Methods: A home-based, 3-month feasibility trial of a distance coaching mHealth program entitled Lifestyle Improvements for Transplant Success (LIFTS) was developed from interviews with 22 kidney wait-list dialysis patients. Program components of the LIFTS program include: 1) A walking program using Fitbit devices and app (Charge 2/Alta HR or latest model in line) to track steps on non-dialysis days, 2) Muscle strengthening using video education (links to You-Tube TM), 3) Renal disease nutrition and physical education using weekly videos, 4) Nutrition tracking using MyFitness-Pal app and 5) Weight/fluid variability tracking using Nokia (formerly Withings) Wi-Fi scales and inclusive smartphone app. Activity steps and weight were remotely monitored in real-time and goals modified by an online coach every two weeks. Acceptability was primary assessed from exit interview content and quantified apps' measures to assess program components' use along with physical function and psychosocial changes. Results: One White male (age 45) and 2 Black women (ages 24, 35) were recruited. Findings demonstrated: (1) Support of using Fitbits in walking program, but some wear ability/technical issues (i.e., 98%, 82%, and 29% wear adherence), (2) Support using weight scales (mean = 2.54 weigh-ins/week), (3) Nonadherence to suspension training protocols, suggesting need for a different approach, (4) Dietary videos were helpful, (5) The dietary tracking app was too burdensome and (6) Participants interested in more social elements and challenges. Overall, all participants felt the program improved their health. Conclusions: Futher methodology refinement guided by dialysis patients to enhance acceptability is needed prior to a subsequent pilot study. Findings may be applicable in mHealth designs in highly fatigued patients.

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