TY  - JOUR
T1  - ASsociation of physical activity and body composition with insulin sensitivity in a community sample of adolescents
AU  - Snitker S, Le KY, Hager E, Caballero B, Black MM
Y1  - 2007/07/01
N1  - 10.1001/archpedi.161.7.677
JO  - Archives of Pediatrics & Adolescent Medicine
SP  - 677
EP  - 683
VL  - 161
IS  - 7
N2  - Objective 
    To examine how body composition and physical activity are related to insulin sensitivity and secretion in adolescents.Design 
    Cross-sectional.Setting 
    Baltimore, Maryland.Participants 
    Fifty-six healthy adolescents (34 boys and 22 girls; mean [SD] age, 13.3 [1.3] years; 95% were African American) who had been recruited at infancy from a health care clinic serving a low-income, urban community.Main Exposures 
    Physical activity was measured for 5 to 7 days by a uniaxial accelerometer placed on the right ankle. Proportion of time spent in play-equivalent physical activity (PEPA) was defined as 1800 or more counts per minute. Body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) was converted to an age- and sex-specific z score.Main Outcome Measures 
    Insulin sensitivity, insulin secretion, and disposition index calculated from a fasting oral glucose tolerance test.Results 
    Thirty-nine percent of the adolescents had a BMI in the 85th percentile or higher; half of those were overweight (BMI ≥ 95th percentile). Play-equivalent physical activity and BMI z score were not correlated. In multivariate analyses, BMI z score and time spent in PEPA together explained 21% of the variance in insulin sensitivity and 18% in insulin secretion. Independent of each other, high BMI z score and low proportion of PEPA were significantly associated with low insulin sensitivity (partial r2 = 0.14 and 0.10, respectively) and high insulin secretion (partial r2 = 0.10 and 0.10, respectively), but not with disposition index.Conclusions 
    In a cohort of urban, predominantly African American adolescents, both body composition and physical activity were independently associated with insulin sensitivity. At this point, insulin secretion is appropriately regulated.
SN  - 1072-4710
M3  - doi: 10.1001/archpedi.161.7.677
UR  - http://dx.doi.org/10.1001/archpedi.161.7.677
ER  -