18 results on '"Johnson, William D."'
Search Results
2. Cadence (steps/min) and intensity during ambulation in 6–20 year olds: the CADENCE-kids study
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Tudor-Locke, Catrine, Schuna, Jr, John M., Han, Ho, Aguiar, Elroy J., Larrivee, Sandra, Hsia, Daniel S., Ducharme, Scott W., Barreira, Tiago V., and Johnson, William D.
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- 2018
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3. Short chain acyl-CoA dehydrogenase deficiency and short-term high-fat diet perturb mitochondrial energy metabolism and transcriptional control of lipid-handling in liver.
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Ghosh, Sujoy, Kruger, Claudia, Wicks, Shawna, Simon, Jacob, Kumar, K. Ganesh, Johnson, William D., Mynatt, Randall L., Noland, Robert C., and Richards, Brenda K.
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ANALYSIS of variance ,ANIMAL experimentation ,ENERGY metabolism ,FISHER exact test ,FAT content of food ,FOOD habits ,LIVER ,MICE ,OXIDOREDUCTASES ,POLYMERASE chain reaction ,RESEARCH funding ,T-test (Statistics) ,DATA analysis software ,MICROARRAY technology ,GENE expression profiling ,DESCRIPTIVE statistics ,SHORT-chain fatty acids ,GENOTYPES - Abstract
Background: The liver is an important site of fat oxidation, which participates in the metabolic regulation of food intake. We showed previously that mice with genetically inactivated Acads, encoding short-chain acyl-CoA dehydrogenase (SCAD), shift food consumption away from fat and toward carbohydrate when tested in a macronutrient choice paradigm. This phenotypic eating behavior suggests a link between fat oxidation and nutrient choice which may involve an energy sensing mechanism. To identify hepatic processes that could trigger energy-related signals, we have now performed transcriptional, metabolite and physiological analyses in Acads-/-mice following short-term (2 days) exposure to either high- or low-fat diet. Methods and Results: Metabolite analysis revealed 25 acylcarnitine species that were altered by diet and/or genotype. Compared to wild-type mice, phosphorylated AMP-activated protein kinase was 40 % higher in Acads-/- mice after short-term high-fat diet, indicating a low ATP/AMP ratio. Metabolite analyses in isolated liver mitochondria from Acads-/-mice during ADP-linked respiration on butyrate demonstrated a reduced oxygen consumption rate (OCR) compared to wild-type, an effect that was not observed with succinate or palmitoylcarnitine substrates. Liver transcriptomic responses in Acads-/- mice fed high- vs. lowfat diet revealed increased RXR/PPARA signaling, up-regulation of lipid handling pathways (including beta and omega oxidation), and increased mRNA expression of Nfe2l2 target genes. Conclusions: Together, these results point to an oxidative shortage in this genetic model and support the hypothesis of a lower hepatic energy state associated with SCAD deficiency and high-fat diet. [ABSTRACT FROM AUTHOR]
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- 2016
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4. Examination of mechanisms (E-MECHANIC) of exercise-induced weight compensation: study protocol for a randomized controlled trial.
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Myers, Candice A., Johnson, William D., Earnest, Conrad P., Rood, Jennifer C., Tudor-Locke, Catrine, Johannsen, Neil M., Cocreham, Shannon, Harris, Melissa, Church, Timothy S., and Martin, Corby K.
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WEIGHT loss , *EXERCISE , *ENERGY consumption , *BODY mass index , *RANDOMIZED controlled trials , *HUMAN body composition - Abstract
Background Weight loss induced only by exercise is frequently less than expected, possibly because of compensatory changes in energy intake and/or energy expenditure. The purpose of the Examination of Mechanisms of Exercise-Induced Weight Compensation (E-MECHANIC) trial is to examine whether increased energy intake and/or reduced spontaneous activity or energy expenditure (outside of structured exercise) account for the less than expected, exercise-associated weight loss. Methods/Design E-MECHANIC is a three-arm, 6-month randomized (1:1:1) controlled trial. The two intervention arms are exercise doses that reflect current recommendations for (1) general health (8 kcal/kg body weight per week (8 KKW), about 900 kcal/wk) and (2) weight loss (20 KKW, about 2,250 kcal/wk). The third arm, a nonexercise control group, will receive health information only. The sample will include a combined total of 198sedentary, overweight or obese (body mass index: ⩾25 kg/m2 to ⩽45 kg/m2) men and women ages 18 to 65 years. The exercise dose will be supervised and tightly controlled in an exercise training laboratory. The primary outcome variables are energy intake, which will be measured using doubly labeled water (adjusted for change in energy stores) and laboratory-based food intake tests, and the discrepancy between expected weight loss and observed weight loss. Secondary outcomes include changes in resting metabolic rate (adjusted for change in body mass), activity levels (excluding structured exercise) and body composition. In an effort to guide the development of future interventions, the participants will be behaviorally phenotyped and defined as those who do compensate (that is, fail to lose the amount of weight expected) or do not compensate (that is, lose the amount of weight expected or more). Discussion In this study, we will attempt to identify underlying mechanisms to explain why exercise elicits less weight loss than expected. This information will guide the development of interventions to increase exercise-induced weight loss and maximize weight loss retention and related health benefits. [ABSTRACT FROM AUTHOR]
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- 2014
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5. The role of meal viscosity and oat beta-glucan characteristics in human appetite control: a randomized crossover trial.
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Rebello, Candida J., Yi-Fang Chu, Johnson, William D., Martin, Corby K., Hongmei Han, Bordenave, Nicolas, Yuhui Shi, O'Shea, Marianne, and Greenway, Frank L.
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APPETITE ,OATS as food ,CEREALS as food ,VISCOSITY ,NUTRITION - Abstract
Background Foods that enhance satiety can help consumers to resist environmental cues to eat, and improve the nutritional quality of their diets. Viscosity generated by oat β-glucan, influences gastrointestinal mechanisms that mediate satiety. Differences in the source, processing treatments, and interactions with other constituents in the food matrix affect the amount, solubility, molecular weight, and structure of the β-glucan in products, which in turn influences the viscosity. This study examined the effect of two types of oatmeal and an oat- based ready-to-eat breakfast cereal (RTEC) on appetite, and assessed differences in meal viscosity and β-glucan characteristics among the cereals. Methods Forty-eight individuals were enrolled in a randomized crossover trial. Subjects consumed isocaloric breakfast meals containing instant oatmeal (IO), old-fashioned oatmeal (SO) or RTEC in random order at least a week apart. Each breakfast meal contained 218 kcal (150 kcal cereal, and 68 kcal milk) Visual analogue scales measuring appetite were completed before breakfast, and over four hours, following the meal. Starch digestion kinetics, meal viscosities, and β-glucan characteristics for each meal were determined. Appetite responses were analyzed by area under the curve. Mixed models were used to analyze response changes over time. Results IO increased fullness (p = 0.04), suppressed desire to eat (p = 0.01) and reduced prospective intake (p < 0.01) more than the RTEC over four hours, and consistently at the 60 minute time-point. SO reduced prospective intake (p = 0.04) more than the RTEC. Hunger scores were not significantly different except that IO reduced hunger more than the RTEC at the 60 minute time-point. IO and SO had higher β-glucan content, molecular weight, gastric viscosity, and larger hydration spheres than the RTEC, and IO had greater viscosity after oral and initial gastric digestion (initial viscosity) than the RTEC. Conclusion IO and SO improved appetite control over four hours compared to RTEC. Initial viscosity of oatmeal may be especially important for reducing appetite. [ABSTRACT FROM AUTHOR]
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- 2014
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6. WalkMore: a randomized controlled trial of pedometer-based interventions differing on intensity messages.
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Tudor-Locke, Catrine, Swift, Damon L., Schuna Jr., John M., Dragg, Amber T., Davis, Allison B., Martin, Corby K., Johnson, William D., and Church, Timothy S.
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PHYSIOLOGICAL aspects of walking ,POSTMENOPAUSE ,CARDIOVASCULAR diseases ,PHYSICAL activity ,EXERCISE ,PEDOMETERS - Abstract
Background Pedometer-based programs have elicited increased walking behaviors associated with improvements in blood pressure in sedentary/low active postmenopausal women, a population at increased risk of cardiovascular disease. Such programs typically encourage increasing the volume of physical activity with little regard for its intensity. Recent advances in commercially available pedometer technology now permit tracking of both steps/day and time in moderate (or greater) intensity physical activity on a daily basis. It is not known whether the dual message to increase steps/day while also increasing time spent at higher intensity walking will elicit additional improvements in blood pressure relative to a message to only focus on increasing steps/day. The purpose of this paper is to present the rationale, study design, and protocols employed in WalkMore, a 3-arm 3-month blinded and randomized controlled trial (RCT) designed to compare the effects of two community pedometer-based walking interventions (reflecting these separate and combined messages) relative to a control group on blood pressure in sedentary/low active post-menopausal women, a population at increased risk of cardiovascular disease. Methods/design 120 sedentary/low active post-menopausal women (45-74 years of age) will be randomly assigned (computer-generated) to 1 of 3 groups: A) 10,000 steps/day (with no guidance on walking intensity/speed/cadence; BASIC intervention, n = 50); B) 10,000 steps/day and at least 30 minutes in moderate intensity (i.e., a cadence of at least 100 steps/min; ENHANCED intervention, n = 50); or a Control group (n = 20). An important strength of the study is the strict control and quantification of the pedometer-based physical activity interventions. The primary outcome is systolic blood pressure. Secondary outcomes include diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow mediated dilation, gait speed, and accelerometer-determined physical activity and sedentary behavior. Discussion This study can make important contributions to our understanding of the relative benefits that walking volume and/or intensity may have on blood pressure in a population at risk of cardiovascular disease. Trial registration ClinicalTrials.gov Record NCT01519583, January 18, 2012 [ABSTRACT FROM AUTHOR]
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- 2014
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7. The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE): design and methods.
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Katzmarzyk, Peter T., Barreira, Tiago V., Broyles, Stephanie T., Champagne, Catherine M., Chaput, Jean-Philippe, Fogelholm, Mikael, Hu, Gang, Johnson, William D., Kuriyan, Rebecca, Kurpad, Anura, Lambert, Estelle V., Maher, Carol, Maia, José, Matsudo, Victor, Olds, Tim, Onywera, Vincent, Sarmiento, Olga L., Standage, Martyn, Tremblay, Mark S., and Tudor-Locke, Catrine
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LIFESTYLES ,CHILDHOOD obesity ,PHYSICAL activity ,SOCIAL groups ,COMMUNITY relations - Abstract
Background: The primary aim of the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) was to determine the relationships between lifestyle behaviours and obesity in a multi-national study of children, and to investigate the influence of higher-order characteristics such as behavioural settings, and the physical, social and policy environments, on the observed relationships within and between countries. Methods/design: The targeted sample included 6000 10-year old children from 12 countries in five major geographic regions of the world (Europe, Africa, the Americas, South-East Asia, and the Western Pacific). The protocol included procedures to collect data at the individual level (lifestyle, diet and physical activity questionnaires, accelerometry), family and neighborhood level (parental questionnaires), and the school environment (school administrator questionnaire and school audit tool). A standard study protocol was developed for implementation in all regions of the world. A rigorous system of training and certification of study personnel was developed and implemented, including web-based training modules and regional in-person training meetings. Discussion: The results of this study will provide a robust examination of the correlates of adiposity and obesity in children, focusing on both sides of the energy balance equation. The results will also provide important new information that will inform the development of lifestyle, environmental, and policy interventions to address and prevent childhood obesity that may be culturally adapted for implementation around the world. ISCOLE represents a multi-national collaboration among all world regions, and represents a global effort to increase research understanding, capacity and infrastructure in childhood obesity. [ABSTRACT FROM AUTHOR]
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- 2013
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8. Cardiovascular risk escalation with caloric excess: a prospective demonstration of the mechanics in healthy adults.
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Gupta, Alok K., Johnson, William D., Johannsen, Darcy, and Ravussin, Eric
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CARDIOVASCULAR diseases risk factors , *HYPEREMIA , *VASCULAR diseases , *BRAIN congestion , *ENDOTHELIAL cells , *ENDOTHELIAL seeding - Abstract
Context: The link between weight gain and cardiovascular risk characterized with circadian blood pressure variability [CBPV] and endothelial function [EF] is unexplored. Objective: To prospectively demonstrate weight gain in healthy adults, increases body fat [BF], enlarges waist circumference [WC], expands visceral adipose tissue [VAT], exacerbates systemic inflammation [sIF], worsens insulin resistance [IR] and enhances functional cardiovascular disease [CVD] risk. Design, setting and participants: Healthy men [n=11] and women [n=3] provided initial and eight-week postcaloric excess anthropometric and fasting laboratory measures. Functional CVD risk assessments: CBPV and resting EF were also obtained with 7-day automatic ambulatory BP monitoring and increased test finger peripheral arterial tone [PAT] relative to control [reported as relative hyperemia index (RHI)], respectively. Intervention: After determining individualized mean energy requirements for weight maintenance over 7-days, each participant received a personalized over feeding prescription (1.4 times; 41% carbohydrate, 44% fat, and 15% protein) for 8-weeks. Results: mean (SEM). Participants increased body weight [BW; +7.4(0.1) kg]*, body mass index [BMI; +2.5(0.2) kg/m2]*, BF [+2.0(0.01)%]*, WC [+8.2(1.0) cm]*, and VAT [+0.2(0.03) L]* and intrahepatic lipid [IHL + 0.0004(0.002) L] :*all p < 0.01. Increased subcutaneous adipose cell size [+0.3(0.01) ?L; p = 0.02] accompanied significant sIF [hs-CRP + 0.4(0.09) mg/dL; p = 0.04; leptin 6.63 ng/ml; p = 0.0008] and IR [fasting plasma glucose; [FPG] +7.0(0.6) mg/dL;p = 0.01, fasting insulin; [FI] +5.7(1.4) uIU/ml; p = 0.001, HOMA-IR +1.6(0.5); p = 0.02]. Abn CBPV {systolic [+5.4(0.8); p = 0.002, diastolic [+1.7(0.1); p = 0.07 and pulse pressure [PP] [+3.5(0.4); p = 0.003 mm Hg} or elevated heart rate [HR] [+4.9(0.5) bpm; p = 0.003] ensued. Resting RHI declined by 0.47(0.004) from initial 2.24(0.09) to 1.77(0.1); p = 0.001, indicating endothelial dysfunction [ED]. Conclusions: Controlled caloric excess in healthy human adults over only 8-weeks significantly increased BF, VAT, sIF [hs-CRP], IR [FPG, FI, HOMA-IR] and functional CVD risk [measured as abnormal circadian blood pressure variability and impaired resting endothelial function]. [ABSTRACT FROM AUTHOR]
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- 2013
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9. Adult self-reported and objectively monitored physical activity and sedentary behavior: NHANES 2005--2006.
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Schuna Jr, John M., Johnson, William D., and Tudor-Locke, Catrine
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ACCELEROMETERS , *QUESTIONNAIRES , *SELF-evaluation , *DATA analysis , *SECONDARY analysis , *EXERCISE intensity , *SEDENTARY lifestyles , *PHYSICAL activity , *DESCRIPTIVE statistics , *ADULTS - Abstract
Background: It remains unclear what people are attempting to communicate, in terms of objectively monitored behavior, when describing their physical activity and sedentary behavior through self-report. The purpose of this study was to examine various objectively monitored accelerometer variables (e.g., moderate-to-vigorous physical activity [MVPA], steps/day, sedentary time, etc.) across categories of self-reported MVPA (< 150 vs. ≥ 150 minutes/week), usual occupational/domestic activity (UODA; “mostly sitting” vs. “stand, walk, lift, or carry”), and leisure-time sedentary behavior (LTSB; ≥ 3 vs. < 3 hours/day) in a nationally representative sample of U.S. adults (≥ 20 years). Methods: This is a secondary analysis of 3,725 participants from the 2005–2006 National Health and Nutrition Examination Survey (NHANES) who provided relevant questionnaire responses and ≥ 1 day of valid accelerometer data. Descriptive statistics were computed for various objectively monitored accelerometer variables across categories of self-reported MVPA, UODA, and LTSB. Pairwise comparisons were conducted to examine differences in objectively monitored behavior between categories of self-reported MVPA, UODA, and LTSB. Results: On average, adults reporting compliance with physical activity guidelines (≥ 150 minutes/week of MVPA) accumulated more objectively measured physical activity and similar amounts of sedentary time relative to those reporting not achieving guidelines. Adults reporting their daily UODA as “mostly sitting” or accruing ≥3 hours/day of LTSB accumulated less objectively monitored physical activity and more sedentary time than those who described their UODA as “stand, walk, lift, or carry” or accrued < 3 hours/day of LTSB. The most active cross-classified category (7,935 steps/day; ≥ 150 minutes/week of self-reported MVPA, “stand, walk, lift, or carry” UODA, and < 3 hours/day of LTSB) accumulated more than twice as many daily steps as the least active cross-classified category (3,532 steps/day; < 150 minutes/week of self-reported MVPA, “mostly sitting” UODA, and ≥ 3 hours/day of LTSB). Conclusions: A number of objectively monitored physical activity indicators varied significantly between self-reported MVPA, UODA, and LTSB categories, while objectively monitored sedentary time only varied between UODA and LTSB categories. Cross-classifications of self-reported MVPA, UODA, and LTSB responses depict a greater range of physical activity than viewing dichotomous responses for these variables one-at-a-time. [ABSTRACT FROM AUTHOR]
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- 2013
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10. Steps/day translation of the moderate-to-vigorous physical activity guideline for children and adolescents.
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Adams, Marc A., Johnson, William D., and Tudor-Locke, Catrine
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ACCELEROMETERS , *CHILDREN'S health , *GAIT in humans , *RESEARCH funding , *ADOLESCENT health , *EVIDENCE-based medicine , *PROFESSIONAL practice , *PEDOMETERS , *RECEIVER operating characteristic curves , *PHYSICAL activity , *DATA analysis software , *CHILDREN - Abstract
Background: An evidence-based steps/day translation of U.S. federal guidelines for youth to engage in ≥60 minutes/day of moderate-to-vigorous physical activity (MVPA) would help health researchers, practitioners, and lay professionals charged with increasing youth's physical activity (PA). The purpose of this study was to determine the number of free-living steps/day (both raw and adjusted to a pedometer scale) that correctly classified children (6-11 years) and adolescents (12-17 years) as meeting the 60-minute MVPA guideline using the 2005-2006 National Health and Nutrition Examination Survey (NHANES) accelerometer data, and to evaluate the 12,000 steps/day recommendation recently adopted by the President's Challenge Physical Activity and Fitness Awards Program. Methods: Analyses were conducted among children (n = 915) and adolescents (n = 1,302) in 2011 and 2012. Receiver Operating Characteristic (ROC) curve plots and classification statistics revealed candidate steps/day cut points that discriminated meeting/not meeting the MVPA threshold by age group, gender and different accelerometer activity cut points. The Evenson and two Freedson age-specific (3 and 4 METs) cut points were used to define minimum MVPA, and optimal steps/day were examined for raw steps and adjusted to a pedometer-scale to facilitate translation to lay populations. Results: For boys and girls (6-11 years) with ≥ 60 minutes/day of MVPA, a range of 11,500-13,500 uncensored steps/day for children was the optimal range that balanced classification errors. For adolescent boys and girls (12-17) with ≥60 minutes/day of MVPA, 11,500-14,000 uncensored steps/day was optimal. Translation to a pedometer-scaling reduced these minimum values by 2,500 step/day to 9,000 steps/day. Area under the curve was ≥84% in all analyses. Conclusions: No single study has definitively identified a precise and unyielding steps/day value for youth. Considering the other evidence to date, we propose a reasonable 'rule of thumb' value of ≥ 11,500 accelerometer-determined steps/day for both children and adolescents (and both genders), accepting that more is better. For practical applications, 9,000 steps/day appears to be a more pedometer-friendly value. [ABSTRACT FROM AUTHOR]
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- 2013
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11. Pedometer determined physical activity tracks in African American adults: The Jackson Heart Study.
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Newton Jr., Robert L., Hongmei Han M., Dubbert, Patricia M., Johnson, William D., Hickson, DeMarc A., Ainsworth, Barbara, Carithers, Teresa, Taylor, Herman, Wyatt, Sharon, and Tudor-Locke, Catrine
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BLACK people ,ANALYSIS of variance ,CONFIDENCE intervals ,STATISTICAL correlation ,EPIDEMIOLOGY ,HABIT ,LONGITUDINAL method ,RESEARCH funding ,STATURE ,T-test (Statistics) ,PEDOMETERS ,DATA analysis ,BODY mass index ,LIFESTYLES ,REPEATED measures design ,PHYSICAL activity ,DATA analysis software ,DESCRIPTIVE statistics - 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 FROM AUTHOR]
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- 2012
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12. Prediabetes and prehypertension in disease free obese adults correlate with an exacerbated systemic proinflammatory milieu.
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Gupta, Alok K. and Johnson, William D.
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PREDIABETIC state ,BLOOD pressure ,HYPERTENSION ,DRUG resistance ,NUTRITION disorders ,DIABETES complications ,INSULIN resistance - 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 <100 mg/dL) women and men compared with healthy obese with prediabetes (FSG 100-125 mg/dL) had no significant differences for age (Mean ± SD: 52 ± 12 vs. 56 ± 9 y), weight (95 ± 11 vs. 99 ± 13 kg), or waist circumference (108 ± 10 vs. 108 ± 11 cm). Normoglycemic group (n = 24; W = 19, M = 5) had normal FSG 92 ± 4 mg/dL, HbA1c 5.4 ± 0.3%, BP 118/75 mm Hg, but had elevated high sensitivity C-reactive protein (hs CRP) 3.7 ± 3 mg/L and fibrinogen 472 ± 76 mg/dL. The group with prediabetes (n = 11; W = 8, M = 3) with significantly higher FSG (106 ± 3 mg/dL; p < 0.0001), HbA1c (5.9 ± 0.5%; p < 0.002), had prehypertension (BP: 127/80 mm Hg) and significantly higher hs CRP (16.9 ± 9 mg/; p < 0.0001) and fibrinogen (599 ± 95 mg/dL; p < 0.0002). Conclusions: In otherwise healthy disease free obese adults, a higher degree of systemic inflammation is associated with prediabetes and prehypertension. [ABSTRACT FROM AUTHOR]
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- 2010
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13. Accelerometer profiles of physical activity and inactivity in normal weight, overweight, and obese U.S. men and women.
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Tudor-Locke, Catrine, Brashear, Meghan M., Johnson, William D., and Katzmarzyk, Peter T.
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PHYSICAL fitness ,HEALTH & Nutrition Examination Survey ,NUTRITION surveys ,ACCELEROMETERS ,PHYSICAL fitness for men ,MEN'S health ,WOMEN'S health - 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 FROM AUTHOR]
- Published
- 2010
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14. Abnormalities in circadian blood pressure variability and endothelial function: pragmatic markers for adverse cardiometabolic profiles inasymptomatic obese adults.
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Gupta, Alok K., Cornelissen, Germaine, Greenway, Frank L., Dhoopati, Vijay, Halberg, Franz, and Johnson, William D.
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CARDIOVASCULAR diseases ,BLOOD pressure ,OVERWEIGHT persons ,MEDICAL research ,QUANTITATIVE research ,BIOTECHNOLOGY - 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/m
² , 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 FROM AUTHOR]- Published
- 2010
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15. The role of meal viscosity and oat β-glucan characteristics in human appetite control: a randomized crossover trial.
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Rebello, Candida J, Chu, Yi-Fang, Johnson, William D, Martin, Corby K, Han, Hongmei, Bordenave, Nicolas, Shi, Yuhui, O'Shea, Marianne, and Greenway, Frank L
- Abstract
Background: Foods that enhance satiety can help consumers to resist environmental cues to eat, and improve the nutritional quality of their diets. Viscosity generated by oat β-glucan, influences gastrointestinal mechanisms that mediate satiety. Differences in the source, processing treatments, and interactions with other constituents in the food matrix affect the amount, solubility, molecular weight, and structure of the β-glucan in products, which in turn influences the viscosity. This study examined the effect of two types of oatmeal and an oat-based ready-to-eat breakfast cereal (RTEC) on appetite, and assessed differences in meal viscosity and β-glucan characteristics among the cereals.Methods: Forty-eight individuals were enrolled in a randomized crossover trial. Subjects consumed isocaloric breakfast meals containing instant oatmeal (IO), old-fashioned oatmeal (SO) or RTEC in random order at least a week apart. Each breakfast meal contained 218 kcal (150 kcal cereal, and 68 kcal milk) Visual analogue scales measuring appetite were completed before breakfast, and over four hours, following the meal. Starch digestion kinetics, meal viscosities, and β-glucan characteristics for each meal were determined. Appetite responses were analyzed by area under the curve. Mixed models were used to analyze response changes over time.Results: IO increased fullness (p = 0.04), suppressed desire to eat (p = 0.01) and reduced prospective intake (p < 0.01) more than the RTEC over four hours, and consistently at the 60 minute time-point. SO reduced prospective intake (p = 0.04) more than the RTEC. Hunger scores were not significantly different except that IO reduced hunger more than the RTEC at the 60 minute time-point. IO and SO had higher β-glucan content, molecular weight, gastric viscosity, and larger hydration spheres than the RTEC, and IO had greater viscosity after oral and initial gastric digestion (initial viscosity) than the RTEC.Conclusion: IO and SO improved appetite control over four hours compared to RTEC. Initial viscosity of oatmeal may be especially important for reducing appetite. [ABSTRACT FROM AUTHOR]- Published
- 2014
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16. Dysglycemia induces abnormal circadian blood pressure variability.
- Author
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Kumarasamy S, Gopalakrishnan K, Kim DH, Abraham NG, Johnson WD, Joe B, and Gupta AK
- Subjects
- Adiponectin blood, Animals, Biomarkers blood, Blood Pressure Monitoring, Ambulatory, Chemokine CCL2 blood, Diet, High-Fat, Disease Models, Animal, Heart Rate, Inflammation blood, Inflammation etiology, Inflammation Mediators blood, Leptin blood, Prediabetic State blood, Prediabetic State etiology, Rats, Rats, Inbred Dahl, Telemetry, Time Factors, Tumor Necrosis Factor-alpha blood, Weight Gain, Blood Glucose metabolism, Blood Pressure, Circadian Rhythm, Inflammation physiopathology, Prediabetic State physiopathology
- 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.
- Published
- 2011
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17. Abnormalities in circadian blood pressure variability and endothelial function: pragmatic markers for adverse cardiometabolic profiles in asymptomatic obese adults.
- Author
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Gupta AK, Cornelissen G, Greenway FL, Dhoopati V, Halberg F, and Johnson WD
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- Adult, Aged, Biomarkers metabolism, Body Weight physiology, Comorbidity, Female, Humans, Hyperglycemia epidemiology, Hyperglycemia metabolism, Hyperglycemia physiopathology, Inflammation epidemiology, Inflammation metabolism, Inflammation physiopathology, Male, Middle Aged, Prognosis, Risk Factors, Blood Pressure physiology, Cardiovascular Diseases epidemiology, Cardiovascular Diseases metabolism, Cardiovascular Diseases physiopathology, Circadian Rhythm physiology, Endothelium, Vascular metabolism, Endothelium, Vascular physiopathology, Obesity epidemiology, Obesity metabolism, Obesity physiopathology
- 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.
- Published
- 2010
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18. Body mass index and health related quality of life in elementary school children: a pilot study.
- Author
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Zhang L, Fos PJ, Johnson WD, Kamali V, Cox RG, Zuniga MA, and Kittle T
- Subjects
- Body Weight, Child, Child, Preschool, Female, Health Status, Humans, Male, Mississippi, Parent-Child Relations, Parents, Pilot Projects, Proxy, Psychometrics, Schools, Social Adjustment, Surveys and Questionnaires, Body Mass Index, Health Status Indicators, Overweight psychology, Psychology, Child, Quality of Life, Thinness psychology
- 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.
- Published
- 2008
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