Relationship between quantitative ultrasound, anthropometry and sports participation in college aged adults

The college years are an opportune timepoint of intervention in the primary prevention of osteoporosis. Physical activity is an important modifiable risk factor, yet national surveys reveal that young people are insufficiently active. To determine patterns of physical activity associated with improved skeletal status at this life stage, we assessed the relationship between self-reported physical activity patterns, grip strength, anthropometric measures, and calcaneal quantitative ultrasound (QUS) measures in a study of college students (n=235), the Tufts Longitudinal Health Study (TLHS). Univariate analyses revealed several highly significant relationships between QUS parameters and anthropometry, but only among women, with the highest correlation for skeletal muscle mass. Grip strength was significantly related to broadband attenuation (BUA) and stiffness index (SI) in both men and women. Multiple regression analysis revealed that among the modifiable body composition compartments, muscle mass but not fat mass was significantly associated with higher BUA in men (P<0.05) and women (P<0.001), and higher SI in women (P<0.001). Among our sample of college students, current weight training (P=0.004), and moderate (P=0.003) and vigorous (P<0.001) sports participation were each significantly associated with higher SI. Multiple regression analysis revealed that sports participation (moderate and/or vigorous) was associated with higher SI by 10.22+/-3.93 units (P=0.011) among men and 7.28+/-2.36 units (P=0.002) among women. These data suggest that improved skeletal status in young adulthood may require more specific moderate to vigorous physical activity, such as that achieved with sport, than is currently recommended for overall health.