Identification of and Associations among Low, Middle, and High Body Composition Trajectories from Age 5- to 17-Years

Our objective was to identify sex-specific age 5- to 17-year body composition (body mass index (BMI), % body fat, fat mass index, fat-free mass index) trajectories, compare trajectories assigned using age 5 (AGE5) data to those assigned using all available (ALL) data, and compare BMI assignments to other body composition assignments. Cluster analysis was used to identify low, medium, and high trajectories from body composition measures obtained from dual energy x-ray absorptiometry (DXA) scans at 5, 9, 11, 13, 15, and 17 years in a birth cohort followed longitudinally (n = 469). Moderate agreement was observed for comparisons between AGE5 data and ALL data cluster assignments for each body composition measure. Agreement between cluster assignments for BMI and other body composition measures was stronger using ALL data than using AGE5 data. Our results suggest that BMI, % body fat, fat mass index, and fat free mass index trajectories are established during early childhood, and that BMI is a reasonable predictor of body composition appropriate to track obesity in public health and clinical settings.

Abdominal Adiposity Measured by Sonography as a Tool for Determining Disease Risk

A preexperimental cohort study was conducted with 67 overweight cancer survivors. This cohort of participants was screened for baseline body composition and anthropometrics based on a variety of techniques, including body mass index (BMI), dual X-ray absorptiometry–percentage body fat (DXA-android %BF), diagnostic medical sonography (DMS), and waist circumference (WC). The combination of subcutaneous fat layer at the xyphoid and umbilicus compared with BMI, WC, and DXA-android %BF. These variables demonstrated moderately positive association and were statistically significant. A total maximum mean score of DMS measures of subcutaneous and visceral fat was also compared with BMI, WC, and DXA-android %BF. The aforementioned comparison had a moderately positive association and was statistically significant. The sonographic measure of mesentery fat was compared with WC and demonstrated a strongly positive strength of association and was statistically significant. Sonography may be an inexpensive, noninvasive, portable, and valid body composition measure for overweight patients.