Pediatric obesity typically induces insulin resistance, often later evolving into type 2 diabetes. While exercise, enhancing insulin sensitivity, is broadly used to prevent this transition, it is unknown whether alterations in the exercise insulin response pattern occur in obese children. Therefore, we measured exercise insulin responses in 57 healthy weight (NW), 20 overweight (OW), and 56 obese (Ob) children. Blood samples were drawn before and after 30min of intermittent (2min on, 1min off) cycling at ~80% VO2max. In a smaller group (14 NW, 6 OW, 15 Ob), a high-fat meal was ingested 45 min preexercise. Baseline glycemia was similar and increased slightly and similarly in all groups during exercise. Basal insulin (pmol/L) was significantly higher in Ob vs. other groups; postexercise, insulin increased in NW (+7 ± 3) and OW (+5 ± 8), but decreased in Ob (−15 ±5, p < .0167 vs. NW). This insulin drop in Ob was disproportionately more pronounced in the half of Ob children with higher basal insulin (Ob-H). In all groups, high-fat feeding caused a rapid rise in insulin, promptly corrected by exercise. In Ob, however, insulin rose again 30 min postexercise. Our data indicates a distinct pattern of exercise-induced insulin modulation in pediatric obesity, possibly modulated by basal insulin concentrations.
Brian D. Tran, Szu-Yun Leu, Stacy Oliver, Scott Graf, Diana Vigil and Pietro Galassetti
Gregory W. Heath
Regular physical activity has been demonstrated to protect against coronary heart disease, Type 2 diabetes mellitus, selected cancers, hypertension, obesity, and other chronic conditions. Therefore, the public health significance of promoting physical activity and preventing inactivity has become a well-established agenda for public health agencies at all levels.
A secondary search of the literature, focusing on existing evidence reviews, was conducted to identify effective or promising public health physical activity interventions. Further examination of published evidence-based programs also was carried out to supplement the known evidence base. Intervention strategies were selected using criteria prescribed by each of the systematic reviews to yield categories of intervention effectiveness.
The selected physical activity interventions conformed to the domains identified by The Guide to Community Preventive Services. Recommended evidenced-based strategies from within the domain of informational approaches include 2 exemplary community-wide campaigns; mass media campaigns, represented by VERB; and an emerging practice of delivery of short physical activity messages at key community sites. Exemplary representative behavioral/social interventions include social support through organized walking clubs/partners within communities. Exemplary environmental/policy approaches include creating/enhancing access to places for physical activity with informational outreach activities and the emerging strategy of community-wide policies and planning.
Cindy Lentino, Amanda J. Visek, Karen McDonnell and Loretta DiPietro
An innovative strategy for helping people achieve recommended levels of daily physical activity is dog walking. We assessed differences in physical activity and risk indicators between dog owners who 1) walk their dog (n = 399) and 2) do not walk their dog (n = 137) and compared them with adults who do not own dogs (n = 380).
Participants (39 ± 13 years) were recruited online and completed an electronic questionnaire. Healthy People 2010 risk indicators included physical activity, overweight status, tobacco use, nutrition behaviors, chronic conditions, depressive symptoms, and social support.
Compared with dog walkers, those who did not own or walk their dog reported less physical activity (MET-min·week−1) and a higher body mass index (P < .01). Moreover, after adjusting for age and moderate to high physical activity, those who did not own dogs had significantly greater odds of self-reported diabetes [OR = 2.53; 95%CI (1.17−5.48)], hypertension [OR = 1.71; 95%CI (1.03−2.83)], hypercholesterolemia [OR = 1.72; 95%CI (1.06−2.81)], and depression [OR = 1.49; 95%CI (1.09−2.05)] compared with participants who regularly walked their dogs.
Because of the health benefits associated with dog walking, this activity should be encouraged within communities as a method of promoting and sustaining a healthy lifestyle.
Bruce A. Reeder, Karen E. Chad, Elizabeth L. Harrison, Nigel L. Ashworth, M. Suzanne Sheppard, Koren L. Fisher, Brenda G. Bruner, Brian G. Quinn, Punam Pahwa and M. Alomgir Hossain
The study aimed to compare the effectiveness of a class-based (CB) and home-based (HB) exercise program for older adults with chronic health conditions.
172 sedentary older adults with overweight or obesity, type 2 diabetes, hypertension, dyslipidemia, or osteoarthritis were enrolled in a randomized controlled trial with a 3-month follow-up.
A significant increase was seen in the CB group in the Physical Activity Scale for the Elderly (PASE) scores and SF-12 Physical and Mental Health scores. In both groups, significant increases were seen in 6-minute walk distance, Physical Performance Test (PPT), and Functional Fitness Test (FFT), and significant reductions were seen in systolic and diastolic blood pressure but not body mass index or waist circumference. Except for a greater increment in the FFT in the CB group, the degree of improvement was not significantly different between the 2 groups.
After a 3-month intervention, both the CB and HB program produced comparable significant improvements in outcome measures.
Simone A. Kaptein and Elizabeth M. Badley
To examine physical activity (PA) prevalence in individuals with arthritis in comparison with those with other chronic diseases.
Descriptive analyses were based on cross-sectional self-reported data for adults over age 18 from the Canadian Community Health Survey administered in 2005 (N = 132,221) for the following groups: arthritis, back problems, other physical chronic conditions (ie, diabetes, heart disease, hypertension, and cancer), and no physical chronic conditions.
The arthritis group did less leisure-time physical activity than the other 3 groups, they were particularly less likely to engage in vigorous physical activities, but were just as likely to walk when commuting for errands, work, or school. Older women in the arthritis group appeared to be the least active across physical activities and groups.
Adults with chronic disease were more physically inactive during leisure than those without chronic physical conditions, and older women in the arthritis group were particularly limited in our study. A more comprehensive assessment of all types of physical activity, including work, leisure, and commuting behaviors, need to be done in populations with chronic disease, to provide a more accurate portrayal of physical activity participation.
Bronwyn Kay Clark, Takemi Sugiyama, Genevieve N. Healy, Jo Salmon, David W. Dunstan, Jonathan E. Shaw, Paul Z. Zimmet and Neville Owen
Sedentary behaviors, particularly television viewing (TV) time, are associated with adverse health outcomes in adults, independent of physical activity levels. These associations are stronger and more consistent for women than for men.
Multivariate regression models examined the sociodemographic correlates of 2 categories of TV time (≥2 hours/day and ≥4 hours/day); in a large, population-based sample of Australian adults (4950 men, 6001 women; mean age 48.1 years, range 25–91) who participated in the 1999/2000 Australian Diabetes, Obesity, and Lifestyle (AusDiab) study.
Some 46% of men and 40% of women watched ≥ 2 hours TV/day; 9% and 6% respectively watched ≥ 4 hours/day. For both men and women, ≥2 hours TV/day was associated with less than tertiary education, living outside of state capital cities, and having no paid employment. For women, mid and older age (45−64 and 65+) were also significant correlates of ≥2 hours TV/day. Similar patterns of association were observed in those viewing ≥4 hours/day.
Prolonged TV time is associated with indices of social disadvantage and older age. These findings can inform the understanding of potential contextual influences and guide preventive initiatives.
Rachel G. Walker, Joyce Obeid, Thanh Nguyen, Hilde Ploeger, Nicole A. Proudfoot, Cecily Bos, Anthony K. Chan, Linda Pedder, Robert M. Issenman, Katrin Scheinemann, Maggie J. Larché, Karen McAssey and Brian W. Timmons
The objectives of this study were to (i) assess sedentary time and prevalence of screen-based sedentary behaviors of children with a chronic disease and (ii) compare sedentary time and prevalence of screen-based sedentary behaviors to age- and sex-matched healthy controls. Sixty-five children (aged 6-18 years) with a chronic disease participated: survivors of a brain tumor, hemophilia, type 1 diabetes mellitus, juvenile idiopathic arthritis, cystic fibrosis, and Crohn’s disease. Twenty-nine of these participants were compared with age- and sex-matched healthy controls. Sedentary time was measured objectively by an ActiGraph GT1M or GT3x accelerometer worn for 7 consecutive days and defined as less than 100 counts per min. A questionnaire was used to assess screen-based sedentary behaviors. Children with a chronic disease engaged in an average of 10.2 ± 1.4 hr of sedentary time per day, which comprised 76.5 ± 7.1% of average daily monitoring time. There were no differences between children with a chronic disease and controls in sedentary time (adjusted for wear time, p = .06) or in the prevalence of TV watching, and computer or video game usage for varying durations (p = .78, p = .39 and, p = .32 respectively). Children with a chronic disease, though relatively healthy, accumulate high levels of sedentary time, similar to those of their healthy peers.
Toben F. Nelson, Steven L. Gortmaker, S. V. Subramanian and Henry Wechsler
Vigorous physical activity (VPA) declines from adolescence into adulthood and social disparities in VPA exist. Physical activity is understudied in the college setting.
VPA during high school and college was examined among 10,437 students attending 119 four-year colleges using gender-stratified logistic regression analyses.
Fewer students engaged in VPA in college compared with high school (males 74% to 52%; females 68% to 44%). Athletics was associated with VPA, but 51% participated in high school and 15% in college. Among females, African Americans, Asians, and students of lower socioeconomic position (SEP) were less likely to engage in VPA in college, adjusting for high school VPA. Among males, Asians and older students were less likely to engage in VPA.
VPA declines from high school to college. Athletic participation is a determinant of VPA, but few participate in collegiate athletics. Social disparities in VPA emerge in college, an important setting for promoting VPA and addressing health disparities. Regular physical activity is an important contributor to human health. It is positively associated with longevity and may prevent or help manage diabetes, metabolic syndrome, overweight, hypertension, cardiovascular disease, and colon cancer.1-8 Among children and adolescents, lack of physical activity is associated with higher body mass index.9-10 Physical activity is also associated with positive mood, self-esteem, and decreased anxiety.11-14
Yanmei Niu, Hong Yuan and Li Fu
Insulin resistance (IR) is a common pathophysiological feature of Type 2 diabetes. Although the mechanisms leading to IR are still elusive, evidence has shown that aerobic exercise can reverse this process. To investigate the effects of aerobic exercise on IR, the authors created an IR animal model by feeding C57BL/6 mice a high-fat diet for 8 wk. They then compared the effect of 6 wk of treadmill training (60 min/d) at 75% VO2max on mice in normal-diet (NE) and high-fat-diet (HE) groups with their sedentary control groups. Levels of skeletal-muscle AMPKα (AMP-activated protein kinase α), ACC (acetyl-CoA carboxylases), and CPT1 (carnitine palmitoyltransferase 1) mRNA and AMPKα, pAMPK-Thr172, ACC, pACC-Ser79, and CPT1 protein expressions were analyzed. In addition, fasting serum levels of insulin, triglyceride, and cholesterol were measured. The results demonstrate that 6 wk of exercise increased AMPKα mRNA expression by 11% and 25 % (p < .01) in the NE and HE groups, respectively, and AMPKα protein expression by 37.9% and 20.1% (p < .01) in NE and HE compared with their sedentary control. In addition, ACC mRNA and protein expressions declined, whereas CPT1 mRNA and protein expressions were elevated in both exercise groups compared with sedentary control groups. In addition, pAMPK-Thr172 and pACC-Ser79 expression increased significantly in the NE and HE groups compared with sedentary control groups. In conclusion, our results demonstrate that 6 wk of aerobic exercise can effectively ameliorate IR by increasing the expression of AMPKα and pAMPK-Thr172, thereby activating the key enzymes that facilitate lipid metabolism.
Bo Hu, Xiaoyu Liu, Chenggang Wang, Sufeng Yin, Liqun Yu, Tianzhe Zhang, Jianhui Wu, Yinping Chen, Yao Zheng and Fumin Feng
To examine the association and relative contribution of different levels of physical activity (PA) with metabolic syndrome (MS).
The cluster sampling method was used to recruit 8,750 communitybased individuals between 40 and 60 years of age. MS was defined according to the International Diabetes Federation, 2005. PA was estimated with the International Physical Activity Questionnaire, and three levels of PA (low, moderate, vigorous) were used to classify the individuals. The risk factors of MS were comprehensively collected, and logistic regression methods were used to measure the association between PA and MS. Population-attributable risks and their 95% confidence intervals (CI) were calculated based on the regression model.
Approximately 30.4% (2,661) of the participants were MS patients. The percentage of individuals with vigorous levels of PA was 46.2% and 43.5% and with low levels of PA was 11.3% and 11.3% in non-MS and MS group, respectively. Individuals with vigorous PA had an odds ratio (OR) of 0.78 (95% CI: 0.66, 0.91) for MS compared with those with low PA, and the OR for individuals with moderate PA was 0.85 (95% CI: 0.73, 1.01). Moderate and vigorous PA levels decreased risk of MS by 18.3%, with approximately 11% of that decrease due to vigorous PA.
Vigorous PA levels were consistently associated with a reduced risk of MS; however, a protective role of moderate PA was not found. The population-attributable risk for vigorous PA was about 11% for all MS risk factors.