Total and regional body volumes in African American women 60 years old with a BMI 35kg/m2

Abstract

It is well known that senior aged adults have marked differences in body composition compared to their younger counterparts. Recent research suggests that as body mass increases there is a disproportionate increase in trunk size compared to that of the extremities (arm and legs). The aim of the current study was to examine the relationship between body mass index (BMI, kg/m2) and the relative volume of the arms (AV) and legs (LV) compared to the truncal (TV) region as a proportion of total body volume (TBV) in African American women ≥60 years old. Participant (n=23) mean age was 71.47 ± 6.80 years and mean BMI was 27.60 ± 4.51 kg/m2 (range 17.84–35.41 kg/m2). TBV and regional volumes (AV, LV, TV) were measured using the validated 3 dimensional photonic scanner (3DPS). Each of the regional volumes were assessed as a proportion of TBV (TV/TBV, AV/TBV, LV/TBV) in order to assess differences in the regional volume relative to overall body volume with increasing BMI. AV/TBV (r=−0.56, p=0.005) and LV/TBV (r=−0.480, p=0.020) were positively associated with BMI. TV/TBV, however, was inversely associated with BMI (r=0.52, p=0.011). These results show that the proportion of TV to TBV increases with BMI while the proportion of AV and LV to TBV decreases with increasing BMI. It may be that in older persons ≥60 years with a BMI between 17–35 kg/m2, increases in weight are largely in the trunk region while weight decreases proportionally to the total body in the extremities (arms and legs).