Least Significant Change of Body Composition and Bone Mineral Density Measured by Dual energy X‐Ray Absorptiometry

Abstract

IntroductionThis study is designed to determine the least significant (LSC), or the least amount of change that can be considered significant when measuring body composition with Dual Energy X‐ray Absorptiometry (DXA). In the past five years, researchers have focused on measuring the LSC of bone mineral DXA scans or body composition DXA scans in athletic populations. However, none have measured LSC for body composition in non‐ athletic populations or the LSC of each component of body composition.MethodsForty‐six adults (39 female; 7 male) partook in the study aged between 50.78 ± 15.27 years. They weighed 157.90 ± 38.83 pounds, and had a of height 64.83 ± 3 inches. Any participant who that was pregnant was excluded from the study. DXA scans for body composition and BMD was taken by the same technician. Each scan was consecutively taken 3 times, and after each scan the participant got up from the table, and was repositioned for the next scan. Results were calculated with the International Society of Clinical Densitometry's calculator.ResultsDXA scans for WB‐ Bone Area, WB‐ BMD, WB‐ Lean Mass + BMC, WB‐ Lean Mass, and WB‐ Total Mass measured less than 1% of coefficient variation, where as AP Spine BMD, WB‐ Bone Mass, WB‐Fat Mass, and WB‐% Body Fat were just over 1%, between 1.07‐ 1.3% coefficient variation. However, the WB‐ VAT Mass had a significantly higher percent (15.9%) coefficient of variation.ConclusionsDXA scans for whole body and spine all come with a 1% error as reported by DXA manufacturers, with the exception of WB VAT mass that had a significantly higher percent error.