• An 8-month exercise intervention alters frontotemporal white matter integrity in overweight children

      Schaeffer, David J.; Krafft, Cynthia E.; Schwarz, Nicolette F.; Chi, Lingxi; Rodrigue, Amanda L.; Pierce, Jordan E.; Allison, Jerry David; Yanasak, Nathan Eugene; Liu, Tianming; Davis, Catherine L.; et al. (2014-08)
      In childhood, excess adiposity and low fitness are linked to poor academic performance, lower cognitive function, and differences in brain structure. Identifying ways to mitigate obesity-related alterations is of current clinical importance. This study examined the effects of an 8-month exercise intervention on the uncinate fasciculus, a white matter fiber tract connecting frontal and temporal lobes. Participants consisted of 18 unfit, overweight 8- to 11-year-old children (94% Black) who were randomly assigned to either an aerobic exercise (n=10) or a sedentary control group (n=8). Before and after the intervention, all subjects participated in a diffusion tensor MRI scan. Tractography was conducted to isolate the uncinate fasciculus. The exercise group showed improved white matter integrity as compared to the control group. These findings are consistent with an emerging literature suggesting beneficial effects of exercise on white matter integrity.
    • An 8-month randomized controlled exercise trial alters brain activation during cognitive tasks in overweight children

      Krafft, Cynthia E.; Schwarz, Nicolette F.; Chi, Lingxi; Weinberger, Abby L.; Schaeffer, David J.; Pierce, Jordan E.; Rodrigue, Amanda L.; Yanasak, Nathan Eugene; Miller, Patricia H.; Tomporowski, Phillip D.; et al. (2014-01)
      Objective Children who are less fit reportedly have lower performance on tests of cognitive control and differences in brain function. This study examined the effect of an exercise intervention on brain function during two cognitive control tasks in overweight children. Design and Methods Participants included 43 unfit, overweight (BMI ≥ 85th percentile) children 8- to 11-years old (91% Black), who were randomly divided into either an aerobic exercise (n = 24) or attention control group (n = 19). Each group was offered a separate instructor-led after-school program every school day for 8 months. Before and after the program, all children performed two cognitive control tasks during functional magnetic resonance imaging (fMRI): antisaccade and flanker. Results Compared to the control group, the exercise group decreased activation in several regions supporting antisaccade performance, including precentral gyrus and posterior parietal cortex, and increased activation in several regions supporting flanker performance, including anterior cingulate and superior frontal gyrus. Conclusions Exercise may differentially impact these two task conditions, or the paradigms in which cognitive control tasks were presented may be sensitive to distinct types of brain activation that show different effects of exercise. In sum, exercise appears to alter efficiency or flexible modulation of neural circuitry supporting cognitive control in overweight children.
    • Adolescent obesity, bone mass, and cardiometabolic risk factors

      Pollock, Norman K.; Bernard, Paul J.; Gutin, Bernard; Davis, Catherine L.; Zhu, Haidong; Dong, Yanbin; GEORGIA PREVENTION INSTITUTE (Elsevier, 2011-05)
      Objective: To compare bone mass between overweight adolescents with and without cardiometabolic risk factors (CMR). Associations of bone mass with CMR and adiposity were also determined. Study design: Adolescents (aged 14 to 18 years) who were overweight were classified as healthy (n = 55), having one CMR (1CMR; n = 46), or having two or more CMR (≥2CMR; n = 42). CMRs were measured with standard methods and defined according to pediatric definitions of metabolic syndrome. Total body bone mass, fat mass, and fat-free soft tissue mass were measured with dual-energy X-ray absorptiometry. Visceral adipose tissue and subcutaneous abdominal adipose tissue were assessed with magnetic resonance imaging. Results: After controlling for age, sex, race, height, and fat-free soft tissue mass, the healthy group had 5.4% and 6.3% greater bone mass than the 1CMR and ≥2CMR groups, respectively (both P values <.04). With multiple linear regression, adjusting for the same co-variates, visceral adipose tissue (β = -0.22), waist circumference (β = -0.23), homeostasis model assessment of insulin resistance (β = -0.23), and high-density lipoprotein cholesterol level (β = 0.22) were revealed to be associated with bone mass (all P values <.04). There was a trend toward a significant inverse association between bone mass and fasting glucose level (P = .056). No relations were found between bone mass and fat mass, subcutaneous abdominal adipose tissue, blood pressure, or triglyceride level. Conclusion: Being overweight with metabolic abnormalities, particularly insulin resistance, low high-density lipoprotein cholesterol level, and visceral adiposity, may adversely influence adolescent bone mass.
    • Aerobic fitness thresholds associated with fifth grade academic achievement

      Wittberg, Richard; Cottrell, Lesley A.; Davis, Catherine L.; Northrup, Karen L.; GEORGIA PREVENTION INSTITUTE (Taylor & Francis Online, 2010)
      Background: Whereas effects of physical fitness and physical activity on cognitive function have been documented, little is known about how they are related. Purpose: This study assessed student aerobic fitness measured by FITNESSGRAM Mile times and/or Pacer circuits and whether the nature of the association between aerobic fitness and standardized academic performance is dose-response or threshold related. Methods: Standardized academic test scores and aerobic capacity scores were collected from two cohorts of 5th grade students over two years. The Mile run and Pacer circuits results were compared to patterns in students’ academic test scores. Results: Sectioning of Mile times and Pacer circuits revealed a sharp peak in academic performance for boys who completed the Mile in 9 minutes or less. Girls’ Pacer revealed peaks in academic performance at 12 and 30 circuits. Discussion: Results demonstrate that select achievements in the Mile or Pacer account for significant increases in academic performance on standardized tests. Translation to Health Education Practice: This study identifies aerobic fitness points which, if achieved, offer the greatest probability of increased academic success in fifth graders. Physical education, cross-curricular thematic units, and club activities can be portals of opportunity to increase moderate to vigorous physical activity and fitness in students. Furthermore, school-based physical activity and fitness opportunities may positively impact health risk factors associated with childhood obesity. Policies that increase aerobic activity opportunities in the school setting may increase overall academic performance, encourage positive health habits and improve immediate and future overall health.
    • Antisaccade-related brain activation in children with attention-deficit/hyperactivity disorder - A pilot study

      Schwarz, Nicolette F.; Krafft, Cynthia E.; Chi, Lingxi; Weinberger, Abby L.; Schaeffer, David J; Pierce, Jordan E.; Rodrigue, Amanda L.; Williams, Celestine F; DiBattisto, Caroline H.; Maria, Bernard L.; et al. (2015-11-30)
      While antisaccade paradigms invoke circuitry associated with cognitive control and attention-deficit/hyperactivity disorder (ADHD), there is a dearth of functional magnetic resonance imaging (fMRI) investigations using antisaccade tasks among children with ADHD. Neural correlates associated with antisaccade performance were examined with fMRI in 11 children with ADHD (10 medicated) matched to 11 typically developing children. Significantly greater brain activation in regions in right dorsolateral prefrontal cortex and caudate nucleus was observed in children with ADHD relative to the control group. This pattern separated the children into their respective groups in a taxonomic manner. Sensitivity analyses probing comorbidity and medication-specific effects showed that results were consistent; however, the caudate nucleus difference was only detectable in the full sample, or in subsets with a more relaxed cluster threshold. Antisaccade performance did not significantly differ between the groups, perhaps as a result of greater brain activation or medication effects in the ADHD group. Thus, antisaccade paradigms may have sensitivity and specificity for the investigation of cognitive control deficits and associated neural correlates in ADHD, and may contribute towards the development of new treatment approaches for children with the disorder.
    • Beyond Genome-Wide Association Studies: New Strategies for Identifying Genetic Determinants of Hypertension

      Wang, Xiaoling; Prins, Bram P.; Sõber, Siim; Laan, Maris; Snieder, Harold; Georgia Institute for Prevention of Human Diseases and Accidents; Department of Pediatrics (2011-12-28)
      Keywords: Linkage analysis
    • Cardiometabolic Biomarkers in Young Black Girls: Relations to Body Fatness and Aerobic Fitness, and Effects of a Randomized Physical Activity Trial

      Gutin, Bernard; Harris, Ryan A.; Howe, Cheryl A.; Johnson, Maribeth H.; Zhu, Haidong; Dong, Yanbin; Georgia Institute for Prevention of Human Diseases and Accidents; Department of Pediatrics; Department of Biostatistics and Epidemiology (2011-10-11)
      There is little evidence from randomized trials showing that physical activity alone influences biomarker profiles in youths. This study tested two hypotheses: (i) that elevated body fatness and poor fitness would be associated with unfavorable levels of cardiometabolic biomarkers in 8- 12-y-old black girls (n = 242) and (ii) that a 10-mo PA intervention would have favorable effects on the fatness-related cardiometabolic biomarkers. At baseline, all fatness indices (i.e., percent body fat, visceral adipose tissue, BMI, and waist circumference) were significantly (P < 0.05) associated with unfavorable levels of insulin, glucose, systolic BP, diastolic BP, triglycerides, C-reactive protein (CRP), and fibrinogen. Aerobic fitness was significantly (P < 0.05) associated with favorable levels of insulin, CRP, fibrinogen, and HDL2. The PA intervention had significant and favorable effects on fitness, fatness, and two biomarkersâ resting heart rate and LDL cholesterol. More research is needed to clarify what types of interventions can enhance the cardiometabolic health of youths.
    • Device-Based Movement Behaviors, Executive Function, and Academic Skills among African American Children with ADHD and Disruptive Behavior Disorders

      Santiago-Rodríguez, María; D. Ramer, Jared; Marquez, David; Frazier, Stacy; Davis, Catherine L.; Bustamante, Eduardo; GEORGIA PREVENTION INSTITUTE (2022-04)
      Background: Physical activity (PA) has been identified as a promising intervention to improve executive function (EF) and reduce ADHD symptoms in children. Few African American children with ADHD and Disruptive Behavior Disorders (DBDs) from families with low incomes are represented in this literature. The purpose of this study is to test the relationships between PA and sedentary time (ST), and EF and academic skills among African American children with ADHD and DBD from low-income families. Methods: Children (n = 23, 6–13 years old) wore an ActiGraph for one week to measure PA and ST. EF was measured through parent report and direct neuropsychological tests. Academic skills were measured with the Curriculum-Based Measurement System. Bivariate correlations tested relationships between PA, ST, EF, and academic skills. Results: A significant correlation was observed between vigorous PA time and parent reported EF (r = −0.46, p = 0.040). Light PA and moderate PA were not related to EF or academic skills, and neither was ST. Conclusions: Vigorous PA may prove useful as an adjunct treatment to improve EF in African American children with ADHD and DBD in low-income neighborhoods. Research using experimental and longitudinal designs, and examining qualitative features of PA experiences, will be critical for understanding relationships between PA, academic skills, and EF in this population.
    • Differential Impact of Stress Reduction Programs upon Ambulatory Blood Pressure among African American Adolescents: Influences of Endothelin-1 Gene and Chronic Stress Exposure

      Gregoski, Mathew J.; Barnes, Vernon A.; Tingen, Martha S.; Dong, Yanbin; Zhu, Haidong; Treiber, Frank A.; Georgia Institute for Prevention of Human Diseases and Accidents; Department of Pediatrics (2011-11-24)
      Stress-activated gene * environment interactions may contribute to individual variability in blood pressure reductions from behavioral interventions. We investigated effects of endothelin-1 (ET-1) LYS198ASN SNP and discriminatory stress exposure upon impact of 12-week behavioral interventions upon ambulatory BP (ABP) among 162 prehypertensive African American adolescents. Following genotyping, completion of questionnaire battery, and 24-hour ABP monitoring, participants were randomized to health education control (HEC), life skills training (LST), or breathing awareness meditation (BAM). Postintervention ABP was obtained. Significant three-way interactions on ABP changes indicated that among ET-1 SNP carriers, the only group to show reductions was BAM from low chronic stress environments. Among ET-1 SNP noncarriers, under low chronic stress exposure, all approaches worked, especially BAM. Among high stress exposure noncarriers, only BAM resulted in reductions. If these preliminary findings are replicated via ancillary analyses of archival databases and then via efficacy trials, selection of behavioral prescriptions for prehypertensives will be edging closer to being guided by individual's underlying genetic and environmental factors incorporating the healthcare model of personalized preventive medicine.
    • Disordered eating behavior in individuals with diabetes: Importance of context, evaluation, and classification

      Young-Hyman, Deborah L.; Davis, Catherine L.; GEORGIA PREVENTION INSTITUTE (American Diabetes Association, 2010-03)
      Limitations of current research findings: Gaps in understanding the association of DEB and diabetes include: lack of weightmatched control subjects when comparing the prevalence of eating disorders or subclinical DEB; evaluation of the contributions of an insulin dosing schedule and overinsulinization (19), loss of satiety mechanisms via hormonal dysregulation, and dietary prescriptions as potential causes perceived as loss of control over food intake; the intent of behavior in those seeking to prevent weight gain secondary to treatment; incomplete psychological characterization of samples, including psychological constructs such as loss of control, autonomy, and selfefficacy over blood glucose and weight; the potential for misclassification of behaviors and attitudes as reflecting DEB when they possibly reflect skills and attitudes learned as part of the diabetes care/self-management regimen; and the need for refinement of existing measurement tools and development of assessment methods that address diabetes-specific attitudes, concerns, and behaviors that are prescribed as part of treatment; as well as physiological mechanisms that are beyond the control of the patient. Most studied cohorts have consisted of subjects that were white, heavier than control samples, recruited from tertiary care centers, and often monitored more frequently and thoroughly than patients receiving care in the community. Sample selection bias may be operating to eliminate well-controlled well-adjusted individuals from clinical studies, potentially selecting individuals most vulnerable to the development of DEB. No studies were identified that monitored patients from the time of diagnosis to establish the temporal sequence of the onset of behavior considered maladaptive and whether weight gain occurs first or the care regimen is manipulated to prevent weight gain. Few studies could be found wherein the comorbidity of depression and other forms of psychological distress and DEB were evaluated. Directions for future research: Evaluation, characterization, and classifi-cation of DEB in individuals with diabetes have clinical importance. However, classification of these behaviors is less clinically informative if population-specific criteria and taxonomy are not established. Further, focusing on identified gaps in future investigations of DEB in this population could improve clinical care for this serious comorbid condition. Studies that chronicle the development of DEB prospectively from diagnosis will allow us to assess the contributions of the many factors that predispose individuals to the development of DEB, potentially identifying approaches to diabetes treatment with a lower risk of iatrogenic complications. It is clinically important to be able to identify those individuals who are at risk for this comorbid condition in association with and independent of the burden of diabetes care. In order to distinguish whether insulin reduction or omission is maladaptive, evaluation of the intent and context of this behavior is needed. Is it a means to regain control over excessive eating by using self-management skills or, in contrast, is it intended as a short-cut weight management strategy (purging via glycosuria)? Physiological mechanisms such as an insulin dose in excess of physiological requirement, hypoglycemia, and a hormonally driven imbalance in hunger, food intake, and experience of satiety appear to be critical factors in establishing diabetes-specific criteria that discriminate between maladaptive manipulations of the diabetes care regimen to control weight and potentially adaptive regimen modifications. Studies are needed that address these distinctions.
    • DPPFit: Developing and Testing a Technology-Based Adaptation of the Diabetes Prevention Program (DPP) to Address Prediabetes in a Primary Care Setting

      Stewart, Jessica; Hatzigeorgiou, Christos; Davis, Catherine L.; Ledford, Christy J.W. (2022-05)
      Objective: The objective of this study was to adapt the National Diabetes Prevention Program (N-DPP) into a pragmatic tool for primary care settings by using daily text messaging to deliver all N-DPP content, supplemented by Fitbit technology to provide behavioral strategies typically delivered by personnel in traditional programs. Test the mobile health (mHealth), technology-based N-DPP adaptation (DPPFit) in primary care patients with prediabetes using a remote intervention based on the traditional 16 core sessions of the DPP. Methods: A pilot study with pre/post survey analysis of aggregate data were used to determine changes in weight, physical activity, sedentary behavior, and associated diabetes risk outcomes among study participants (n = 33). In this study, participants were issued Fitbit devices and provided the remote intervention over 16 weeks via automated text messaging technology, which followed the content of the DPP core education sessions. Results: Data analysis from baseline to 6-month follow-up demonstrate mean weight loss of 3.3 kg (95% CI: -6.2 to -0.5; P = .026), reduction in body mass index by 1.25 points (95% CI: -2.1 to -0.4; P = .005), a significant average increase of 2 days in self-reported physical activity per week (95% CI: 0.4 to 3.6; P = .015) and an average 10% decrease in sedentary time (P = .007). Conclusions: The remote DPPFit intervention demonstrates a promising and practical approach to the management of prediabetes in a primary care setting. The results support the use of the DPPFit program and application to achieve meaningful outcomes in a population with prediabetes. A randomized controlled trial with a larger sample is warranted. ( J Am Board Fam Med 2022;35:548–558.)
    • The Effect of Regular Exercise on Cognition in Special Populations of Children: Overweight and Attention-Deficit Hyperactivity Disorder

      Bustamante, Eduardo; Krafft, Cynthia E.; Schaeffer, David J; McDowell, Jennifer E.; Davis, Catherine L.; GEORGIA PREVENTION INSTITUTE (Elsevier, 2016-01-01)
      Childhood overweight/obesity and ADHD are common conditions of interest to researchers investigating the relationship between regular physical activity and children's cognition. Children in these populations are less physically active and have lower cognitive function than typically developing children. Research may identify the effects of regular exercise on cognition relevant to parents, clinicians, and educators struggling to respond to the growing needs presented by these conditions. Observational studies provide promising preliminary evidence of a relationship between regular exercise and cognition in these populations, but few rigorous randomized controlled trials have been conducted. Early results are encouraging. Future randomized trials promise to shed further light on the efficacy of different physical activity programs, elucidate neurobiological mechanisms that may guide refinement of interventions, and develop evidence-based interventions suitable for broad dissemination.
    • Effects of regular exercise vs sedentary after school program on mood and quality of life of overweight children

      Davis, Catherine L.; Bustamonte, Eduardo E.; Williams, Celestine; Waller, Jennifer L.; Georgia Regents University (2014)
    • An eight month randomized controlled exercise intervention alters resting state synchrony in overweight children

      Krafft, Cynthia E.; Pierce, Jordan E.; Schwarz, Nicolette F.; Chi, Lingxi; Weinberger, Abby L.; Schaeffer, David J.; Rodrigue, Amanda L.; Canchong, J.; Allison, Jerry David; Yanasak, Nathan Eugene; et al. (2014-01-03)
      Children with low aerobic fitness have altered brain function compared to higher-fit children. This study examined the effect of an 8-month exercise intervention on resting state synchrony. Twenty-two sedentary, overweight (body mass index ≥85th percentile) children 8-11. years old were randomly assigned to one of two after-school programs: aerobic exercise (n= 13) or sedentary attention control (n= 9). Before and after the 8-month programs, all subjects participated in resting state functional magnetic resonance imaging scans. Independent components analysis identified several networks, with four chosen for between-group analysis: salience, default mode, cognitive control, and motor networks. The default mode, cognitive control, and motor networks showed more spatial refinement over time in the exercise group compared to controls. The motor network showed increased synchrony in the exercise group with the right medial frontal gyrus compared to controls. Exercise behavior may enhance brain development in children.
    • Endothelial health in childhood acute lymphoid leukemia survivors: Pilot evaluation with peripheral artery tonometry

      Ruble, Kathy; Davis, Catherine L.; Han, Hae Ra; Augusta University (2015-03-06)
      Background: Childhood cancer survivors are a growing population at risk for poor cardiac outcomes. Acute lymphoid leukemia (ALL) survivors are among those at increased risk of cardiovascular complications. Early identification of impaired vascular health may allow for interventions to improve these outcomes. The purpose of this study was to evaluate vascular health using peripheral artery tonometry in ALL survivors and compare results with healthy siblings. Procedure: Sixteen ALL survivor, healthy sibling pairs, aged 8 to 20 years, were evaluated for vascular health and cardiovascular risk factors (body mass index, central adiposity, blood pressure, and fitness). One-tailed paired t test was used to compare the groups. Results: Survivors were similar to siblings in cardiovascular risk measures but had poorer vascular health as measured by reactive hyperemia index (survivor RHI 1.54 vs. sibling 1.77; P=0.0474). Conclusion: This study reveals that even among survivors who are comparable to their healthy siblings in other traditional cardiovascular risks, there is evidence of poorer vascular health.
    • Exercise and academic performance among children with attention-deficit hyperactivity disorder and disruptive behavior disorders: A randomized controlled trial

      D. Ramer, Jared (2020-08)
      Purpose: To examine effects of a 10-week after-school physical activity (PA) program on academic performance of 6- to 12-year-old African American children with behavior problems. Methods: Participants were randomized to PA (n = 19) or sedentary attention control (n = 16) programs. Academic records, curriculum-based measures, and classroom observations were obtained at baseline, postintervention, and/or follow-up. Mixed models tested group × time interactions on academic records and curriculum-based measures. One-way analysis of variance or Kruskal–Wallis tested for differences in postintervention classroom observations. Results: Intent-to-treat analyses demonstrated a moderate effect within groups from baseline to postintervention on disciplinary referrals (PA: d = −0.47; attention control: d = −0.36) and a null moderate effect on academic assessments (PA: d = 0.11 to 0.36; attention control: d = 0.05 to 0.40). No significant group × time interactions emerged on direct academic assessments (all Ps ≥ .05, d = −0.23 to 0.26) or academic records (all Ps ≥ .05, d = −0.28 to 0.16). Classroom observations revealed that intervention participants were off-task due to moving at twice the rate of comparative classmates (F = 15.74, P < .001) and were off-task due to talking 33% more often (F = 1.39, P = .257). Conclusion: Academic outcome improvements were small within and between groups and did not sustain at follow-up. Academic benefits of after-school PA programs for children with attention-deficit hyperactivity disorder and/or disruptive behavior disorders were smaller than neurobiological, behavioral, and cognitive outcomes as previously reported.
    • Exercise dose and diabetes risk in overweight and obese children: A randomized controlled trial

      Davis, Catherine L.; Pollock, Norman K.; Waller, Jennifer L.; Allison, Jerry David; Dennis, B. Adam; Bassali, Reda; Meléndez, Agustín; Boyle, Colleen A.; Gower, Barbara A.; Augusta University (2012-09-12)
      Context: Pediatric studies have shown that aerobic exercise reduces metabolic risk, but dose-response information is not available. Objectives: To test the effect of different doses of aerobic training on insulin resistance, fatness, visceral fat, and fitness in overweight, sedentary children and to test moderation by sex and race. Design, Setting, and Participants: Randomized controlled efficacy trial conducted from 2003 through 2007 in which 222 overweight or obese sedentary children (mean age, 9.4 years; 42% male; 58% black) were recruited from 15 public schools in the Augusta, Georgia, area. Intervention: Children were randomly assigned to low-dose (20 min/d; n=71) or high-dose (40 min/d; n=73) aerobic training (5 d/wk; mean duration, 13 [SD, 1.6] weeks) or a control condition (usual physical activity; n=78). Main Outcome Measures: The prespecified primary outcomes were postintervention type 2 diabetes risk assessed by insulin area under the curve (AUC) from an oral glucose tolerance test, aerobic fitness (peak oxygen consumption [V̇O 2]), percent body fat via dual-energy x-ray absorptiometry, and visceral fat via magnetic resonance, analyzed by intention to treat. Results: The study had 94% retention (n=209). Most children (85%) were obese. At baseline, mean body mass index was 26 (SD, 4.4). Reductions in insulin AUC were larger in the high-dose group (adjusted mean difference, -3.56 [95% CI, -6.26 to -0.85] ×103 μU/mL; P=.01) and the low-dose group (adjusted mean difference, -2.96 [95% CI, -5.69 to -0.22] ×103 μU/mL; P=.03) than the control group. Dose-response trends were also observed for body fat (adjusted mean difference, -1.4% [95% CI, -2.2% to -0.7%]; P<.001 and -0.8% [95% CI, -1.6% to -0.07%]; P=.03) and visceral fat (adjusted mean difference, -3.9 cm3 [95% CI, -6.0 to -1.7 cm3]; P<.001 and -2.8 cm3 [95% CI, -4.9 to -0.6 cm3]; P=.01) in the high- and low-dose vs control groups, respectively. Effects in the high- and low-dose groups vs control were similar for fitness (adjusted mean difference in peak V̇O2, 2.4 [95% CI, 0.4-4.5] mL/kg/min; P=.02 and 2.4 [95% CI, 0.3-4.5] mL/kg/min; P=.03, respectively). High- vs low-dose group effects were similar for these outcomes. There was no moderation by sex or race. Conclusion: In this trial, after 13 weeks, 20 or 40 min/d of aerobic training improved fitness and demonstrated dose-response benefits for insulin resistance and general and visceral adiposity in sedentary overweight or obese children, regardless of sex or race. Trial Registration clinicaltrials.gov Identifier: NCT00108901.
    • Exercise effects on arterial stiffness and heart health in children with excess weight: The SMART RCT

      Davis, Catherine L.; Litwin, Sheldon E; Pollock, Norman K; Waller, Jennifer L; Zhu, Haidong; Dong, Yanbin; Gaston, Kapuku; Bhagatwala, Jigar; Harris, Ryan A; Looney, Jacob; et al. (2020-05-01)
      INTRODUCTION: Childhood obesity and inactivity are associated with cardiovascular risk. Evidence is limited for exercise effects on arterial health in children. METHODS: One hundred and seventy-five inactive children with overweight or obesity (8-11 years, ≥85th percentile BMI, 61% female, 87% Black, 73% with obesity) were randomized to an 8-month daily after-school aerobic exercise program (40 min/day, n = 90) or a sedentary control condition (n = 85). Carotid-femoral pulse wave velocity (PWV, primary outcome, arterial stiffness), fitness, adiposity, blood pressure (BP), glucose, insulin resistance, lipids, and C-reactive protein were measured at baseline and posttest (8 months). Adiposity, fitness, and BP were measured again at follow-up, 8-12 months later. Intent-to-treat analyses were conducted using mixed models. RESULTS: The study had 89% retention, with attendance of 59% in exercise and 64% in the control condition, and vigorous exercise participation (average heart rate 161 ± 7 beats/min). Compared with controls, the exercise group had twice the improvement in fitness (VȮ2 peak, 2.7 (95% CI 1.8, 3.6) vs. 1.3 (0.4, 2.3) mL/kg/min) and adiposity (-1.8 (-2.4, -1.1) vs. -0.8 (-1.5, -0.1)%), each p = 0.04, and a large improvement in HDL-cholesterol (0.13 (0.075, 0.186) vs. -0.028 (-0.083, 0.023) mmol/L, p < 0.0001). There was no group × time effect on other outcomes at 8 months, or on any outcomes at follow-up. The change in PWV at 8 months correlated with changes in insulin and insulin resistance (both r = 0.32), diastolic BP (r = 0.24), BMI (r = 0.22), and adiposity (r = 0.18). CONCLUSIONS: Eight months of aerobic exercise training improved fitness, adiposity, and HDL-cholesterol levels, but did not reduce arterial stiffness in children with excess weight. PWV improved as a function of insulin resistance, BP, BMI, and adiposity. Weight loss may be required to improve arterial stiffness. Exercise benefits waned after discontinuing the program.
    • Exercise effects on depressive symptoms and self-worth in overweight children: a randomized controlled trial

      Petty, Karen H.; Davis, Catherine L.; Tkacz, Joseph; Young-Hyman, Deborah; Waller, Jennifer L; GEORGIA PREVENTION INSTITUTE (Oxford University Press on behalf of the Society of Pediatric Psychology, 2009-10)
      Objective To test the dose–response effects of an exercise program on depressive symptoms and self-worth in children. Method Overweight, sedentary children (N = 207, 7–11 years, 58% male, 59% Black) were randomly assigned to low or high dose (20 or 40 min/day) aerobic exercise programs (13 ± 1.6 weeks), or control group. Children completed the Reynolds Child Depression Scale and Self-Perception Profile for Children at baseline and posttest. Results A dose–response benefit of exercise was detected for depressive symptoms. A race × group interaction showed only White children's global self-worth (GSW) improved. There was some evidence that increased self-worth mediated the effect on depressive symptoms. Conclusions This study shows dose–response benefits of exercise on depressive symptoms and self-worth in children. However, Blacks did not show increased GSW in response to the intervention. Results provide some support for mediation of the effect of exercise on depressive symptoms via self-worth.