Influence Of Socio-economic Status On Habitual Physical Activity In 8- To 10-year-old Children

Abstract

In adults, a lower socio-economic status (SES) is generally associated with lower physical activity (PA) levels; however, findings are inconclusive in children. PURPOSE: The purpose of this study is to examine whether physical activity and/or sedentary behavior differs in children by SES. METHODS: Subjects included 275 (119 males; 156 females) children 8-10 years of age. Height and body mass were assessed according to standard procedures and body mass index (BMI, kg/m2) was calculated. Self-reported household income was used to determine SES and create 5 groups ($100,000). Habitual, free-living PA was assessed by a pedometer. Participants recorded time worn and the number of steps accumulated on each day over a 7-day period. Measures of screen time (TV, computer use, video games) were determined by self-report. Differences in physical activity levels and sedentary behavior by SES were initially tested using ANOVA. Further analyses used ANCOVA controlling for leg length, sex, and BMI. RESULTS: No significant SES group differences were observed for age (total sample 9.6 ± 0.9 years), height (total sample 138.5 ± 8.1 cm), and leg length (total sample 65.7 ± 5.1 cm); however, lower SES individuals had higher body mass and BMI compared to higher SES groups. Mean daily steps also differed significantly among SES groups with lower SES groups approximating 10,500 steps/day compared to about 12,000 steps/day in the higher SES groups. These differences remained significant (p<0.05) when controlling for leg length, but were not significant when further controlling for sex and BMI. Significant differences between SES groups were shown for sedentary behavior as well (P<0.05) with higher SES groups approximating 20 hrs/wk compared to almost 40 hrs/week of TV in lower SES groups and these differences remained significant when controlling for sex and BMI. CONCLUSIONS: Children from a low SES display lower PA levels and spend more time in sedentary behavior; however, differences in PA were influenced by BMI. The higher BMI in these children might be another factor contributing to increased health risks among low SES individuals. Funding provided by Medica Foundation, Healthy and Active America Foundation and Cargill, Inc.