Regional and total body composition assessment and aerobic power in spinal cord injured subjects

Inactivity and obesity may explain the high cardiovascular morbidity in paraplegic (P) subjects. Total and segmental body composition, and maximal aerobic power (VO2max) were assessed in 13 P males (18-45 yrs, lesion levels lower than T5; BW 84±15 kg; BMI 25.7±4.3 kg/m2) and in 13 able-bodied matched controls (C). Fat body mass (FM) by 4-skinfold thickness method, and total and segmental body fat mass, fat free mass (FFM) and bone mineral density (BMD) were measured by DXA. DXA FM was 31.1±8.3% (SD) in P and 20.8±6.9% in C; FFM 51.4±6.3 and 56.2±5.6%, BMD 1.2±0.1 and 1.3±0.1 g/cm2, respectively. Segmental FM is higher (p<0.05) in P than in C, especially in lower limbs (37.3±10.3 vs 20.5±5.2%) and trunk (31.2±8.2 vs 22.3±8.0%). BMD is significantly lower in P in legs only (1.1±0.2 vs 1.5±0.2 g/cm2). Compared with DXA, the skinfold method underestimates FM in P patients (19.6±4.2 vs 22.3±6.8%). VO2max is about halved in P (18.0±6.3 vs 34.0±7.0 ml/kg/min), and a linear negative relationship (r=0.52, p<0.05) between FM and VO2max occurs. In conclusion, in P subjects the changes in total body composition, especially at sublesional level, and the dramatic decrease of aerobic power may represent a high risk for cardiovascular disease. Disagreement between DXA and skinfold method suggests to develop skinfold prediction equations specific to the P subjects. Supported by Ministry of Health and University.