Predicting basal metabolic rate in men with motor complete spinal cord injury: basal metabolic rate in SCI

Purpose This study aimed to assess the accuracy of existing basal metabolic rate (BMR) prediction equations in men with chronic (>1 yr) spinal cord injury (SCI). The primary aim is to develop new SCI population-specific BMR prediction models, based on anthropometric, body composition, and/or demographic variables that are strongly associated with BMR. 
Methods Thirty men with chronic SCI (paraplegic, n = 21, tetraplegic, n = 9) 35 ± 11 yr old (mean ± SD) participated in this cross-sectional study. Criterion BMR values were measured by indirect calorimetry. Body composition (dual-energy x-ray absorptiometry) and anthropometric measurements (circumferences and diameters) were also taken. Multiple linear regression analysis was performed to develop new SCI-specific BMR prediction models. Criterion BMR values were compared with values estimated from six existing and four developed prediction equations. 
Results Existing equations that use information on stature, weight, and/or age significantly (P <0.001) overpredicted measured BMR by a mean of 14%-17% (187-234 kcal·d -1). Equations that used fat-free mass (FFM) accurately predicted BMR. The development of new SCI-specific prediction models demonstrated that the addition of anthropometric variables (weight, height, and calf circumference) to FFM (model 3; r 2 = 0.77), explained 8% more of the variance in BMR than FFM alone (model 1; r 2 = 0.69). Using anthropometric variables, without FFM, explained less of the variance in BMR (model 4; r 2 = 0.57). However, all the developed prediction models demonstrated acceptable mean absolute error ≤6%. 
Conclusion BMR can be more accurately estimated when dual-energy x-ray absorptiometry-derived FFM is incorporated into prediction equations. Using anthropometric measurements provides a promising alternative to improve the prediction of BMR, beyond that achieved by existing equations in persons with SCI.