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Background: Energy expenditure (EE) estimates for a broad age range of youth performing a variety of activities are needed. Methods: 106 participants (6–18 years) completed 6 free-living activities (seated rest, movie watching, coloring, stair climbing, basketball dribbling, jumping jacks) and up to 9 treadmill walking bouts (13.4 to 120.7 m/min; 13.4 m/min increments). Breath-by-breath oxygen uptake (VO2) was measured using the COSMED K4b2 and EE was quantified as youth metabolic equivalents (METy1:VO2/ measured resting VO2, METy2:VO2/estimated resting VO2). Age trends were evaluated with ANOVA. Results: Seated movie watching produced the lowest mean METy1 (6- to 9-year-olds: 0.94 ± 0.13) and METy2 values (13- to 15-year-olds: 1.10 ± 0.19), and jumping jacks produced the highest mean METy1 (13- to 15-year-olds: 6.89 ± 1.47) and METy2 values (16- to 18-year-olds: 8.61 ± 2.03). Significant age-related variability in METy1 and METy2 were noted for 8 and 2 of the 15 evaluated activities, respectively. Conclusions: Descriptive EE data presented herein will augment the Youth Compendium of Physical Activities. [ABSTRACT FROM AUTHOR]

Abstract Background This study investigated the number of pedometer assessment occasions required to establish habitual physical activity in African American adults. Methods African American adults (mean age 59.9 ± 0.60 years; 59 % female) enrolled in the Diet and Physical Activity Substudy of the Jackson Heart Study wore Yamax pedometers during 3-day monitoring periods, assessed on two to three distinct occasions, each separated by approximately one month. The stability of pedometer measured PA was described as differences in mean steps/day across time, as intraclass correlation coefficients (ICC) by sex, age, and body mass index (BMI) category, and as percent of participants changing steps/day quartiles across time. Results Valid data were obtained for 270 participants on either two or three different assessment occasions. Mean steps/day were not significantly different across assessment occasions (p values > 0.456). The overall ICCs for steps/day assessed on either two or three occasions were 0.57 and 0.76, respectively. In addition, 85 % (two assessment occasions) and 76 % (three assessment occasions) of all participants remained in the same steps/day quartile or changed one quartile over time. Conclusion The current study shows that an overall mean steps/day estimate based on a 3-day monitoring period did not differ significantly over 4 – 6 months. The findings were robust to differences in sex, age, and BMI categories. A single 3-day monitoring period is sufficient to capture habitual physical activity in African American adults.

Abstract Background Prediabetes (PreDM) in asymptomatic adults is associated with abnormal circadian blood pressure variability (abnormal CBPV). Hypothesis Systemic inflammation and glycemia influence circadian blood pressure variability. Methods Dahl salt-sensitive (S) rats (n = 19) after weaning were fed either an American (AD) or a standard (SD) diet. The AD (high-glycemic-index, high-fat) simulated customary human diet, provided daily overabundant calories which over time lead to body weight gain. The SD (low-glycemic-index, low-fat) mirrored desirable balanced human diet for maintaining body weight. Body weight and serum concentrations for fasting glucose (FG), adipokines (leptin and adiponectin), and proinflammatory cytokines [monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α)] were measured. Rats were surgically implanted with C40 transmitters and blood pressure (BP-both systolic; SBP and diastolic; DBP) and heart rate (HR) were recorded by telemetry every 5 minutes during both sleep (day) and active (night) periods. Pulse pressure (PP) was calculated (PP = SBP-DBP). Results [mean(SEM)]: The AD fed group displayed significant increase in body weight (after 90 days; p < 0.01). Fasting glucose, adipokine (leptin and adiponectin) concentrations significantly increased (at 90 and 172 days; all p < 0.05), along with a trend for increased concentrations of systemic pro-inflammatory cytokines (MCP-1 and TNF-α) on day 90. The AD fed group, with significantly higher FG, also exhibited significantly elevated circadian (24-hour) overall mean SBP, DBP, PP and HR (all p < 0.05). Conclusion These data validate our stated hypothesis that systemic inflammation and glycemia influence circadian blood pressure variability. This study, for the first time, demonstrates a cause and effect relationship between caloric excess, enhanced systemic inflammation, dysglycemia, loss of blood pressure control and abnormal CBPV. Our results provide the fundamental basis for examining the relationship between dysglycemia and perturbation of the underlying mechanisms (adipose tissue dysfunction induced local and systemic inflammation, insulin resistance and alteration of adipose tissue precursors for the renin-aldosterone-angiotensin system) which generate abnormal CBPV.

Abstract Background Cardiovascular disease (CVD) risk, although perceived to be high, is often difficult to demonstrate in disease free (healthy) obese adults. Hypothesis Changes in circadian blood pressure variability (CBPV) and endothelial function (EF) may be early correlates of cardiometabolic disorders. Methods Asymptomatic men and women in 3 groups: normal weight (n = 10), overweight (n = 10) and obese (n = 15) were evaluated. Blood pressure and heart rate were recorded over 7 days: every 30 minutes during the day and every 60 minutes during the night, by automatic ambulatory monitoring. Resting EF was assessed in a fasting state between 8-10 AM by brachial ultrasound. Anthropometric and cardiometabolic indicators were measured and correlations with CBPV and EF were investigated. Results The 3 groups had (Mean(SD)) BMI: 22.6(1.6), 27(3) and 34(5) kg/m2, respectively, weight: 64(16), 79(14), 95(16) kg and waist circumference: 79(9), 93(10), 107(13) cm. None in normal-weight or overweight groups had abnormal CBPV, while 8 of 15 obese adults had one or more CBPV abnormities (p < 0.05). Obese adults with CBPV abnormalities had elevated hs-CRP (15.3(9.3) mg/L), fibrinogen (593(97) mg/dl), fasting serum glucose (102(16) mg/dL), and cardiac risk ratios (Total-C/HDL-C: 5.2(1.9), LDL-C/HDL-C: 3.1(1.4)). Adults in the 3 respective groups who did not have CBPV abnormalities had flow-mediated brachial artery dilatation (FMD) of 0.22(0.06); 0.20(0.04), 0.23(0.02) mm over resting diameter. Obese participants with CBPV abnormalities (Mesor-hypotension, circadian hyper amplitude tension, elevated pulse pressure), had attenuated FMD at 78, 52, and 56% of resting reference diameter (means 0.18(0.07), 0.12(0.08), and 0.13(0.05) mm; p < 0.05), respectively. Conclusions Asymptomatic obese adults with abnormal CBPV and EF exhibit unfavorable cardiometabolic profiles.

Abstract Background The 2005-2006 National Health and Nutrition Examination Survey (NHANES) is used to describe an accelerometer-derived physical activity/inactivity profile in normal weight (BMI < 25 kg/m2), overweight (25 ≤ BMI < 30 kg/m2), and obese (BMI ≥ 30 kg/m2) U.S. adults. Methods We computed physical activity volume indicators (activity counts/day, uncensored and censored steps/day), rate indicators (e.g., steps/minute), time indicators (employing NHANES activity counts/minute cut points to infer time in non-wear, sedentary, low, light, moderate, and vigorous intensities), the number of breaks in sedentary time (occasions when activity counts rose from < 100 activity/counts in one minute to ≥ 100 activity counts in the subsequent minute), achievement of public health guidelines, and classification by step-defined physical activity levels. Data were examined for evidence of consistent and significant gradients across BMI-defined categories. Results In 2005-2006, U.S adults averaged 6,564 ± SE 107 censored steps/day, and after considering non-wear time, they spent approximately 56.8% of the rest of the waking day in sedentary time, 23.7% in low intensity, 16.7% in light intensity, 2.6% in moderate intensity, and 0.2% in vigorous intensity. Overall, approximately 3.2% of U.S. adults achieved public health guidelines. The normal weight category took 7,190 ± SE 157 steps/day, and spent 25.7 ± 0.9 minutes/day in moderate intensity and 7.3 ± 0.4 minutes/day in vigorous intensity physical activity. The corresponding numbers for the overweight category were 6,879 ± 140 steps/day, 25.3 ± 0.9 minutes/day, and 5.3 ± 0.5 minutes/day and for the obese category 5,784 ± 124 steps/day, 17.3 ± 0.7 minutes/day and 3.2 ± 0.4 minutes/day. Across BMI categories, increasing gradients and significant trends were apparent in males for sedentary time and decreasing gradients and significant trends were evident in time spent in light intensity, moderate intensity, and vigorous intensity. For females, there were only consistent gradients and significant trends apparent for decreasing amounts of time spent in moderate and vigorous intensity. Conclusions Simple indicators of physical activity volume (i.e., steps/day) and time in light, moderate or vigorous intensity physical activity differ across BMI categories for both sexes, suggesting that these should continue to be targets for surveillance.

Abstract Background Obesity is a pro-inflammatory state frequently associated with widespread metabolic alterations that include insulin resistance and deregulation of blood pressure (BP). This cascade of events in some measure explains the susceptibility of obese adults for co-morbid conditions like diabetes mellitus and hypertension. Hypothesis We hypothesized that an elevated systemic proinflammatory burden correlates with dysglycemia and deregulated blood pressure. Methods We analyzed the screening anthropometric and laboratory measures from healthy disease free obese adults (n = 35; women (W) 27, men (M) 8) in a weight loss study. Results Healthy obese normoglycemic (fasting serum glucose: FSG Conclusions In otherwise healthy disease free obese adults, a higher degree of systemic inflammation is associated with prediabetes and prehypertension.

Abstract Background We investigated the relationship between Body Mass Index (BMI) and health-related quality of life (HRQOL) indicated by baseline health status in elementary school children. Methods Data were obtained via parents whose children enrolled in an elementary school, kindergarten to fourth grade, in southern Mississippi in spring 2004. Parents completed the SF-10 for Children™, a brief 10-item questionnaire designed to measure children's HRQOL on a voluntary basis. Results A total of 279 parents completed the questionnaires for their children. On average, physical and psychosocial summary scores, major indicators for HRQOL, were significantly higher among the elementary school children in our study relative to those from U.S. children overall (p < 0.0001 and p = 0.0007, respectively). Males tended to have better physical functioning than their female classmates, whereas females had better psychosocial health. Overall, except for third graders, the physical summary scores increased as grade level increased. The means for psychosocial score fluctuated without a clear pattern over the five grade levels. High level of BMI was significantly associated with children's physical summary scores below 50, a norm used for U.S. children (p = 0.003). Gender and grade were not significant predictors of children's physical and psychosocial scores. Discussion This study can be used as baseline information to track changes over time, in BMI and health status among the elementary school children. In addition, this study can be used to investigate relationships between BMI, health status, intellectual ability, and performance in school. Conclusion The findings suggest that programs designed to encourage children to lose weight in a healthy manner, thus reducing their BMI, could improve the physical and psychosocial health, and subsequently increase HRQOL.

Background: The purpose of this study was to compare steps/day detected by the YAMAX SW-200 pedometer versus the Actigraph GT3X accelerometer in free-living adults. Methods: Daily YAMAX and GT3X steps were collected from a sample of 23 overweight and obese participants (78% female; age = 52.6 ± 8.4 yr.; BMI = 31.0 ± 3.7 m·kg-2). Because a pedometer is more likely to be used in a community-based intervention program, it was used as the standard for comparison. Percent difference (PD) and absolute percent difference (APD) were calculated to examine between-instrument agreement. In addition, days were categorized based on PD: a) under-counting (> -10 PD), b) acceptable counting (-10 to 10 PD), and c) over-counting (> 10 PD). Results: The YAMAX and GT3X detected 8,025 ± 3,967 and 7131 ± 3066 steps/day, respectively, and the outputs were highly correlated (r = .87). Average PD was -3.1% ± 30.7% and average APD was 23.9% ± 19.4%. Relative to the YAMAX, 53% of the days detected by the GT3X were classified as under-counting, 25% acceptable counting, and 23% over-counting. Conclusion: Although the output of these 2 instruments is highly correlated, caution is advised when directly comparing or using their output interchangeably. [ABSTRACT FROM AUTHOR]

Background: Analysis of the 2005-2006 National Health and Nutrition Examination Survey (NHANES) accelerometer data provides the descriptive epidemiology of peak 30-minute cadence (defined as the average steps/min recorded for the 30 highest, but not necessarily consecutive, minutes in a day) and peak 1-minute cadence (defined as the steps/min recorded for the highest single minute in a day) by sex, age, and body mass index (BMI). Methods: Minute-by-minute step data were rank ordered each day to identify the peak 30-minute and I -minute cadences for 3522 adults (20+ years of age) with complete sex, age, and BMI data and at least 1 valid day (ie, 10/24 hours of accelerometer wear) of accelerometer data. Peak values were averaged across days within participants by sex, age, and BMI-defined categories. Results: U.S. adults average a peak 30-minute cadence of 71.1 (men: 73.7, women: 69.6, P< .0001) steps/min and a peak 1-minute cadence of 100.7 (men: 100.9, women: 100.5, P = .54) steps/min. Both peak cadence indicators displayed significant and consistent declines with age and increasing levels of obesity. Conclusions: Peak cadence indicators capture the highest intensity execution of naturally occurring ambulatory activity. Future examination of their relationship with health parameters using cross-sectional, longitudinal, and intervention designs is warranted. [ABSTRACT FROM AUTHOR]

A study of 10 social studies education students at the University of Illinois at Urbana-Champaign focused on consequences of pairing student teachers in a field experience program. Most of the findings suggest that the paired student teacher concept may have constructive implications for budgetary considerations and peer support relationships. (FG)