Associations between left ventricular structure and function with cardiorespiratory fitness and body composition in individuals with cervical and upper thoracic spinal cord injury

Abstract

Study designCross-sectional.ObjectiveIt is known that left ventricular mass (LVM) and cardiorespiratory fitness (CRF) are associated to fat-free mass (FFM). It is unknown if these factors associated with left ventricular (LV) structure and function outcomes in individuals with spinal cord injury (SCI).SettingUniversity-based laboratory.Vancouver, BC, Canada.MethodsThirty-two individuals (aged 40 ± 11 years) with chronic, motor-complete SCI between the fourth cervical and sixth thoracic levels were recruited. Echocardiographic LV parameters and body composition were assessed at rest, as per the recommended guidelines for each technique. CRF was assessed during an incremental arm-cycle exercise test until volitional fatigue. The appropriate bivariate correlation coefficients [i.e., Pearson’s (r) and Spearman’s rank (Rs)] tests were used for normal and non-normal distributed variables, respectively.ResultsLV structure and function parameters were not associated with the indexed peak oxygen consumption (V̇O2peak) [i.e., relative to body weight or FFM] (Rs values ranged from −0.168 to 0.134, all P values > 0.223). The association between peak oxygen pulse and the resting echocardiographic-obtained SV was medium sized (Rs = 0.331, P = 0.069). The LVM associations with FFM and fat mass (FM) were large and small (r = 0.614, P < 0.001 and r = 0.266, P = 0.141, respectively). Associations of absolute V̇O2peak were medium- positive with FFM (Rs = 0.414, P = 0.021) but negative with FM (Rs = −0.332, P = 0.068).ConclusionLV parameters measured at rest are not associated with V̇O2peak in individuals with cervical and upper-thoracic SCI. Given the observed associations between LVM and V̇O2peak with FFM, future studies may consider utilizing FFM for indexing cardiovascular measures following SCI.