Effects of socioeconomic status and acculturation on accelerometer-measured moderate-to-vigorous physical activity among Mexican American adolescents: findings from NHANES 2003-2004.

BACKGROUND Socioeconomic status (SES) and acculturation are potential contributors of adolescent physical activity disparity among ethnic groups in the U.S. However, studies relying on self-report physical activity measures have reported inconsistent findings regarding sociocultural predictors of physical activity. Therefore, the current study examined the main and interactive effects of SES and acculturation on accelerometer-measured moderate-to-vigorous intensity physical activity (MVPA) among Mexican American adolescents. METHODS The National Health and Nutrition Examination Survey 2003-2004 was analyzed. Samples of 153 and 169 Mexican American boys and girls, respectively, were analyzed. SES was indicated by poverty-to-income ratio (PIR); and acculturation was measured by 5-item English preference scales and adolescent and parental country of birth. Regression models were tested separately for boys and girls. RESULTS U.S.-born boys compared with immigrants did more MVPA (β = .48, P < .01). On the contrary, the effect of English preference on MVPA in boys was negative (β = -.05, P < .01) and amplified by higher SES (β = -.02, P < .01). For girls, none of the tested variables were significant. CONCLUSIONS Higher SES was a risk factor for physical inactivity in Mexican American adolescents, by a moderating mechanism. In addition, physical activity promotion efforts need to consider English speaking and immigrant Mexican American adolescent boys as a target population.