Body composition assessment in athletes with spinal cord injury: comparison of field methods with dual-energy X-ray absorptiometry.

STUDY DESIGN: Cross-sectional.

OBJECTIVES: To compare relative body fatness (%Fat) estimates from field methods (skinfold thickness measurement (SKF) and bioelectrical impedance analysis (BIA)) with measures by dual-energy X-ray absorptiometry (DXA).

SETTING: University of Illinois, Urbana-Champaign, IL, USA.

METHODS: Field methods used both three- and seven-site SKF prediction equations and BIA generalized, spinal cord injury (SCI)-specific and athlete-specific equations. DXA was used as the reference method. College-aged varsity athletes with SCI (women=8, men=8; time since injury 16.2+/-5.7 years; injury level range T5-L5) were recruited.

RESULTS: Mean BMI was 20.8+/-2.6 and 22.5+/-2.1 kg m(-2), and mean DXA %Fat was 31.9+/-3.8 and 20.6+/-8.4%, for women and men, respectively. All field methods under-predicted the %Fat when compared with DXA (ranges in mean differences: SKF women 2.9-8.2%, SKF men 6.9-12.4%; BIA women 0.5-3.9%, BIA men 0.3-7.0%). None of the field methods accurately predicted the %Fat compared with DXA (total error (TE): SKF women 7.4-12.1%, SKF men 8.4-15.2%; BIA women 5.1-9.3%, BIA men 6.7-10.7%). Of the SKF and BIA prediction equations, Evans et al.'s three-site SKF (r=0.95, P<0.001, standard error of the estimate (SEE)=2.8 %Fat) prediction equation provided the best fit for this population.

CONCLUSION: Further studies with larger samples are necessary to develop appropriate prediction equations for field methods in the athletic SCI population.