Comparison of fat mass percentage and body mass index in Koreans with spinal cord injury according to the severity and duration of motor paralysis

Abstract

Objective: To analyze the relationship of the change in fat mass percentage (FMP) and body mass index (BMI) with the change in obesity rate according to gender, extent of spinal cord injury (SCI) and the duration.Methods The retrospective study was conducted with medical records of 915 patients. FMP was calculated with BMI and bioelectrical impedance analysis (BIA). Statistical analysis of the relationship between FMP and gender, extent of SCI and the duration after SCI was done. Results: FMP increased in relation to the duration. The mean FMP was higher in the motor complete tetraplegia group, as compared to the motor incomplete group. The rate of obesity was 69.8% with cutoff FMP values of over 22% and 35% for male and female patients, respectively. Rate of obesity was correlated with the duration after SCI and degree of paralysis. The rate of obesity was 17.1% with a cutoff value of BMI 25 kg/m2 and 51.3% with a cutoff value of 22 kg/m2. For evaluation of the diagnostic value of BMI to predict obesity according to FMP standards, a cutoff value of 25 kg/m2 showed a sensitivity level of 22.3% and specificity level of 94.9%. When the cutoff level for BMI was set at 22 kg/m2, the sensitivity and specificity were 59.3% and 67.0%, respectively. Conclusion: In Korean SCI patients, FMP showed good correlation with the duration of SCI and the extent of SCI, while BMI did not. Especially in the motor complete tetraplegia group, the diagnostic value of BMI decreased as the duration after SCI increased. This study suggested that FMP could be used complementarily when evaluating the obesity of SCI patients.