Increased physical activity and reduced adiposity in overweight Hispanic adolescents

Sports Participation from Childhood to Adolescence is Associated with Lower Body Dissatisfaction in Boys-A Sex-Specific Analysis

OBJECTIVES

This study aimed to analyze the association between body dissatisfaction and sports participation from childhood to adolescence in a school-based sample of adolescents, according to sex.

METHODS

A total of 1011 adolescents of 13.1 ± 2.3 years of age were evaluated. Body dissatisfaction was assessed by the Silhouettes Scale and sports participation for at least one consecutive year was retrospectively assessed by closed specific questions related to childhood and adolescence periods. Body mass index (BMI) and abdominal obesity were objectively measured. Habitual practice of physical activity (PA), socioeconomic status (SES), and ethnicity were assessed through questionnaires.

RESULTS

Sports participation from childhood to adolescence was observed in 55.1% of boys and in 41.2% of girls. Boys with body dissatisfaction showed lower habitual PA in leisure time (Baecke score = 4.38 ± 2.27 vs. 5.15 ± 2.25, p < 0.05) and in total (Baecke score = 9.34 ± 2.64 vs. 9.96 ± 2.68, p < 0.05) than those who were satisfied. No differences were observed among girls. Sports participation from childhood to adolescence was associated with 42% less chance of having body dissatisfaction in boys (OR = 0.58 [95%CI = 0.36-0.94]). No significant association was observed among girls.

CONCLUSIONS FOR PRACTICE

Sports participation from childhood to adolescence was negatively associated with body dissatisfaction in boys. The continuity of physical activity during youth may be an important modifiable factor to reduce body dissatisfaction.

Accelerometer-Determined Physical Activity and Clinical Low Back Pain Measures in Adolescents With Chronic or Subacute Recurrent Low Back Pain

Study Design Cross-sectional. Background Although low back pain (LBP) occurs commonly in adolescence, little is known about the relationship between objectively measured physical activity and chronic LBP. Objectives To assess the relationship between an objective physical activity measure (accelerometer) and standard clinical measures (pain intensity, disability, and quality of life) in a sample of adolescents with recurrent or chronic LBP. Methods The study included a subsample of 143 adolescents, 12 to 18 years of age, from a randomized clinical trial. Pearson correlations (r) and bivariate linear regression were used to assess the relationship between baseline measures of sedentary, light, and moderate-to-vigorous physical activity using accelerometers and clinical measures of LBP (pain intensity, disability, and quality of life). Results Participants spent an average of 610.5 minutes in sedentary activity, 97.6 minutes in light physical activity, and 35.6 minutes in moderate-to-vigorous physical activity per day. Physical activity was very weakly associated with clinical measures of LBP (r<0.13). None of the assessed correlations were statistically significant, and bivariate regression models showed that physical activity measures explained very little of the variability for clinical measures of LBP (R²<0.02). Conclusion We found no important relationship between objectively measured physical activity and self-reported LBP intensity, disability, or quality of life in adolescents with recurrent or chronic LBP. The parent randomized clinical trial was registered at ClinicalTrials.gov (NCT01096628). J Orthop Sports Phys Ther 2017;47(10):769-774. Epub 12 Sep 2017. doi:10.2519/jospt.2017.7345.

Associations between physical activity and BMI, body fatness, and visceral adiposity in overweight or obese Latino and non-Latino adults

Background/Objectives

Although several studies have reported associations between moderate to vigorous physical activity (MVPA), body fatness, and visceral adipose tissue (VAT), the extent to which associations differ among Latinos and non-Latinos remains unclear. The present study evaluated the associations between body composition and MVPA in Latino and non-Latino adults.

Subjects/Methods

An exploratory, cross-sectional analysis was conducted using baseline data collected from 298 overweight adults enrolled in a 12-month randomized controlled trial that tested the efficacy of text messaging to improve weight loss. MVPA, body fatness and VAT were assessed by waist-worn accelerometry, DXA, and DXA-derived software (GE CoreScan GE, Madison, WI) respectively. Participants with less than 5 days of accelerometry data or missing DXA data were excluded; 236 participants had complete data. Multivariable linear regression assessed associations between body composition and MVPA per day, defined as time in MVPA, bouts of MVPA (time per bout ≥10 min), non-bouts of MVPA (time per bout <10 min), and meeting the 150-minute MVPA guideline. The modifying influence of ethnicity was modeled with a multiplicative interaction term.

Results

The interaction between ethnicity and MVPA in predicting percent body fat was significant (p = 0.01, 95% CI [0.58, 4.43]) such that a given increase in MVPA was associated with a greater decline in total body fat in non-Latinos compared to Latinos (adjusted for age, sex and accelerometer wear time). There was no interaction between ethnicity and MVPA in predicting VAT (g) (p = 0.78, 95% CI [−205.74, 273.17]) and BMI (p = 0.18, 95% CI [−0.49, 2.26]).

Conclusions

An increase in MVPA was associated with a larger decrease in body fat, but neither BMI nor VAT, in non-Latinos compared to Latinos. This suggests that changes in VAT and BMI in response to MVPA may be less influenced by ethnicity than is total body fatness.

Are physical activity studies in Hispanics meeting reporting guidelines for continuous monitoring technology? A systematic review

BACKGROUND

Continuous monitoring technologies such as accelerometers and pedometers are the gold standard for physical activity (PA) measurement. However, inconsistencies in use, analysis, and reporting limit the understanding of dose-response relationships involving PA and the ability to make comparisons across studies and population subgroups. These issues are particularly detrimental to the study of PA across different ethnicities with different PA habits. This systematic review examined the inclusion of published guidelines involving data collection, processing, and reporting among articles using accelerometers or pedometers in Hispanic or Latino populations.

METHODS

English (PubMed; EbscoHost) and Spanish (SCIELO; Biblioteca Virtual en Salud) articles published between 2000 and 2013 using accelerometers or pedometers to measure PA among Hispanics or Latinos were identified through systematic literature searches. Of the 253 abstracts which were initially reviewed, 57 met eligibility criteria (44 accelerometer, 13 pedometer). Articles were coded and reviewed to evaluate compliance with recommended guidelines (N = 20), and the percentage of accelerometer and pedometer articles following each guideline were computed and reported.

RESULTS

On average, 57.1 % of accelerometer and 62.2 % of pedometer articles reported each recommended guideline for data collection. Device manufacturer and model were reported most frequently, and provision of instructions for device wear in Spanish was reported least frequently. On average, 29.6 % of accelerometer articles reported each guideline for data processing. Definitions of an acceptable day for inclusion in analyses were reported most frequently, and definitions of an acceptable hour for inclusion in analyses were reported least frequently. On average, 18.8 % of accelerometer and 85.7 % of pedometer articles included each guideline for data reporting. Accelerometer articles most frequently included average number of valid days and least frequently included percentage of wear time.

DISCUSSION

Inclusion of standard collection and reporting procedures in studies using continuous monitoring devices in Hispanic or Latino population is generally low.

CONCLUSIONS

Lack of reporting consistency in continuous monitoring studies limits researchers' ability to compare studies or draw meaningful conclusions concerning amounts, quality, and benefits of PA among Hispanic or Latino populations. Reporting data collection, computation, and decision-making standards should be required. Improved interpretability would allow practitioners and researchers to apply scientific findings to promote PA.

Step-count guidelines referenced on 60-minutes of moderate/vigorous physical activity

The purpose of this study was to establish step-count guidelines for sixth-grade students and assess the ability of step-counts to discriminate between students achieving and not achieving 60-minutes of moderate to vigorous physical activity daily. 201 sixth-grade students completed the study. They wore a pedometer and an accelerometer at the waist level for one full day. ROC curves were used to establish step-count guidelines and determine the diagnostic accuracy of step-counts. Sixth grade students need 12,118 steps/day to reach adequate daily levels of physical activity. The AUC indicated good diagnostic accuracy of step-counts. Suggested step-count guidelines can be a useful tool for identifying children who need to increase their daily levels of physical activity. The step-count cutoff proposed in this study is adequate for discriminating between sixth grade students reaching and not reaching recommended levels of physical activity.

Vegetable consumption is linked to decreased visceral and liver fat and improved insulin resistance in overweight Latino youth

There are limited data on the influence of vegetable consumption on adiposity and metabolic health, specifically nonstarchy vegetables and vegetables that are dark green and deep orange/yellow (also known as nutrient-rich vegetables). Our study examines the relationship between vegetable intake and adiposity, liver fat, and insulin dynamics in overweight Latino youth. This cross-sectional study of 175 overweight (body mass index ≥85th percentile) Latino youth (aged 8 to 18 years), with data collected during 2006-2011, included the following: dietary intake via multiple 24-hour recalls, total body fat via dual-energy x-ray absorptiometry, adipose tissue distribution and liver fat via magnetic resonance imaging, and insulin dynamics via frequently sampled intravenous glucose tolerance test. Linear regression and analysis of covariance were used for analysis, with the following a priori covariates: age, sex, energy intake, and total body fat. Participants who consumed the most nonstarchy vegetables (mean intake=1.7±1.0 servings/day) compared with the least (mean intake=0.1±0.1 servings/day) had 44% less liver fat (10.0%±8.5% vs 5.6%±8.7%; P=0.01). Nutrient-rich vegetable intake was positively correlated with insulin sensitivity (r=0.19; P=0.03). Consumers of nutrient-rich vegetables (mean intake=0.3±0.4 servings/day [n=107]), compared with nonconsumers (n=68), had 31% increased insulin sensitivity (1.6±1.6 vs 2.1±1.3×10(⁻⁴)/min/μU/mL; P=0.03) and 17% less visceral adipose tissue (2.3±0.9 vs 1.9±0.7 L; P=0.01). Consumption of specific vegetable types by overweight Latino youth is associated with positive metabolic outcomes, including reduced visceral and liver fat and risk factors for type 2 diabetes, even when consumed in small quantities. These may be relevant targets for interventions.

Locations of joint physical activity in parent-child pairs based on accelerometer and GPS monitoring

BACKGROUND

Parental factors may play an important role in influencing children's physical activity levels.

PURPOSE

This cross-sectional study sought to describe the locations of joint physical activity among parents and children.

METHODS

Parent-child pairs (N = 291) wore an Actigraph GT2M accelerometer and GlobalSat BT-335 global positioning systems (GPS) device over the same 7-day period. Children were ages 8-14 years. Joint behavior was defined by a linear separation distance of less than 50 m between parent and child. Land use classifications were assigned to GPS datapoints.

RESULTS

Joint physical activity was spread across residential locations (35 %), and commercial venues (24 %), and open spaces/parks (20 %). Obese children and parents performed less joint physical activity in open spaces/parks than under/normal weight children and parents (ps < 0.01).

CONCLUSIONS

Understanding where joint parent-child physical activity naturally occurs may inform location-based interventions to promote these behaviors.

Joint physical activity and sedentary behavior in parent-child pairs

PURPOSE

The research examined joint physical activity and sedentary behavior among 291 parent-child pairs who both wore an accelerometer and Global Positioning System (GPS) device during the same 7-d period.

METHODS

Children were 52.2% female, 8-14 yr, and 43.0% Hispanic. Parents were 87.6% female. An ActiGraph GT2M accelerometer and GlobalSat BT-335 GPS device collected activity and global positioning data, respectively. Linear distance between the parent and child for each 30-s epoch was calculated using geographic coordinates from the GPS. Joint behavior was defined as a separation distance less than 50 m between parents and children.

RESULTS

On average, during nonschool waking hours, parents and children spent 2.4 ± 4.1 min·d (mean ± SD) performing moderate-to-vigorous physical activity (MVPA) together and 92.9 ± 40.1 min·d in sedentary behavior together. Children engaged in an average of 10 min·d of MVPA during nonschool waking hours when their parent was nearby but not engaging in MVPA. During this same period, parents engaged in 4.6 min·d of MVPA when their child was nearby but not engaging in MVPA. Household income level and the child's age were negatively associated with joint MVPA. Girls engaged in a greater percentage of their total MVPA together with their parent than boys. Girls and older children engaged in more sedentary behavior together with their parent than boys and younger children. Older parents engaged in a greater percentage of their sedentary behavior together with their children than younger parents.

CONCLUSIONS

Replacing the time that parents and children spend together in sedentary pursuits with joint physical activity could have health benefits, especially for girls, older children, older parents, and higher income families.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18

BACKGROUND

The World Health Organization (WHO) estimates that 1.9 million deaths worldwide are attributable to physical inactivity and at least 2.6 million deaths are a result of being overweight or obese. In addition, WHO estimates that physical inactivity causes 10% to 16% of cases each of breast cancer, colon, and rectal cancers as well as type 2 diabetes, and 22% of coronary heart disease and the burden of these and other chronic diseases has rapidly increased in recent decades.

OBJECTIVES

The purpose of this systematic review was to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents.

SEARCH METHODS

The search strategy included searching several databases to October 2011. In addition, reference lists of included articles and background papers were reviewed for potentially relevant studies, as well as references from relevant Cochrane reviews. Primary authors of included studies were contacted as needed for additional information.

SELECTION CRITERIA

To be included, the intervention had to be relevant to public health practice (focused on health promotion activities), not conducted by physicians, implemented, facilitated, or promoted by staff in local public health units, implemented in a school setting and aimed at increasing physical activity, included all school-attending children, and be implemented for a minimum of 12 weeks. In addition, the review was limited to randomized controlled trials and those that reported on outcomes for children and adolescents (aged 6 to 18 years). Primary outcomes included: rates of moderate to vigorous physical activity during the school day, time engaged in moderate to vigorous physical activity during the school day, and time spent watching television. Secondary outcomes related to physical health status measures including: systolic and diastolic blood pressure, blood cholesterol, body mass index (BMI), maximal oxygen uptake (VO2max), and pulse rate.

DATA COLLECTION AND ANALYSIS

Standardized tools were used by two independent reviewers to assess each study for relevance and for data extraction. In addition, each study was assessed for risk of bias as specified in the Cochrane Handbook for Systematic Reviews of Interventions. Where discrepancies existed, discussion occurred until consensus was reached. The results were summarized narratively due to wide variations in the populations, interventions evaluated, and outcomes measured.

MAIN RESULTS

In the original review, 13,841 records were identified and screened, 302 studies were assessed for eligibility, and 26 studies were included in the review. There was some evidence that school-based physical activity interventions had a positive impact on four of the nine outcome measures. Specifically positive effects were observed for duration of physical activity, television viewing, VO2 max, and blood cholesterol. Generally, school-based interventions had little effect on physical activity rates, systolic and diastolic blood pressure, BMI, and pulse rate. At a minimum, a combination of printed educational materials and changes to the school curriculum that promote physical activity resulted in positive effects.In this update, given the addition of three new inclusion criteria (randomized design, all school-attending children invited to participate, minimum 12-week intervention) 12 of the original 26 studies were excluded. In addition, studies published between July 2007 and October 2011 evaluating the effectiveness of school-based physical interventions were identified and if relevant included. In total an additional 2378 titles were screened of which 285 unique studies were deemed potentially relevant. Of those 30 met all relevance criteria and have been included in this update. This update includes 44 studies and represents complete data for 36,593 study participants. Duration of interventions ranged from 12 weeks to six years.Generally, the majority of studies included in this update, despite being randomized controlled trials, are, at a minimum, at moderate risk of bias. The results therefore must be interpreted with caution. Few changes in outcomes were observed in this update with the exception of blood cholesterol and physical activity rates. For example blood cholesterol was no longer positively impacted upon by school-based physical activity interventions. However, there was some evidence to suggest that school-based physical activity interventions led to an improvement in the proportion of children who engaged in moderate to vigorous physical activity during school hours (odds ratio (OR) 2.74, 95% confidence interval (CI), 2.01 to 3.75). Improvements in physical activity rates were not observed in the original review. Children and adolescents exposed to the intervention also spent more time engaged in moderate to vigorous physical activity (with results across studies ranging from five to 45 min more), spent less time watching television (results range from five to 60 min less per day), and had improved VO2max (results across studies ranged from 1.6 to 3.7 mL/kg per min). However, the overall conclusions of this update do not differ significantly from those reported in the original review.

AUTHORS' CONCLUSIONS

The evidence suggests the ongoing implementation of school-based physical activity interventions at this time, given the positive effects on behavior and one physical health status measure. However, given these studies are at a minimum of moderate risk of bias, and the magnitude of effect is generally small, these results should be interpreted cautiously. Additional research on the long-term impact of these interventions is needed.

Physical activity and 3-year BMI change in overweight and obese children

OBJECTIVES

Targeting physical activity (PA) is a mainstay in obesity treatment, but its BMI benefits are poorly quantified. We studied long-term predictive PA-BMI relationships in overweight/obese children presenting to primary care.

METHODS

Three-year follow-up of 182 overweight/obese 5- to 10-year-olds recruited from 45 Melbourne general practices.

PREDICTOR

7-day accelerometry (counts per minute, cpm).

OUTCOMES

change in BMI z score, BMI category, and clinically significant BMI improvement (z score change ≥0.5).

ANALYSIS

Linear and logistic regression.

RESULTS

Mean (SD) baseline and 3-year BMI z scores were 1.8 (0.6) and 1.8 (0.7), and mean (SD) activity scores 334 (111) and 284 (104) cpm, respectively. Baseline activity did not predict BMI change. However, for every 100 cpm increase in change in activity over 3 years, BMI z score fell by 0.11 (95% confidence interval [CI] 0.03-0.20; P = .006). There were also trends toward greater odds of staying in the same, versus moving to a higher, BMI category (odds ratio 1.85, 95% CI 0.99-3.46) and clinically significant BMI improvement (odds ratio 1.96, 95% CI 0.90-4.27; P = .09). Change in percentage time spent in moderate-vigorous (P = .01), but not sedentary (P = .39) or light (P = .59), activity predicted reduced BMI z score.

CONCLUSIONS

Sustained increase in moderate-vigorous PA predicts reducing BMI z score over 3 years in overweight/obese children presenting to primary care. However, the small BMI change associated with even the largest activity changes may explain disappointing BMI outcomes of brief primary care interventions targeting PA.

Increasing Physical Activity Decreases Hepatic Fat and Metabolic Risk Factors

This study assessed the changes in time spent in moderate to vigorous physical activity (MVPA) on fat depots, insulin action, and inflammation. Longitudinal data were generated from 66 Hispanic adolescents (15.6±1.1 yr; BMI percentile 97.1±3.0) who participated in a 16-wk nutrition or nutrition+exercise intervention. There were no effects of the intervention on PA, but there were inter-individual changes in PA. For purposes of this analysis, all intervention groups were combined to assess how changes in PA during 16 wk affected changes in adiposity, insulin action, and markers of inflammation. MVPA was assessed by 7-day accelerometry, total body fat via DXA, liver fat by MRI, and insulin, glucose and HOMA-IR via a fasting blood draw. A repeated measures ANCOVA was used to assess the effect of MVPA on fat depots, insulin action, and inflammatory markers. Sixty-two percent of participants increased MVPA (mean increase, 19.7±16.5 min/day) and 38% decreased MVPA (mean decrease, 10.7±10.1 min/day). Those who increased MVPA by as little as 20 min per day over 16 wk, compared to those who decreased MVPA, had significant reductions in liver fat (-13% vs. +3%; P=0.01), leptin levels (-18% vs. +4%; P=0.02), and fasting insulin (-23% vs. +5%; P=0.05). These findings indicate that a modest increase in MVPA can improve metabolic health in sedentary overweight Hispanic adolescents.