Abstract
Reduced cardiovascular function is common following high spinal cord injury (SCI), yet it is unknown whether cardiac structure and function are related to SCI-induced changes in body composition and metabolic profiles. The objective of this study was to examine the correlation between cardiac structure and function and body composition and metabolic profiles after SCI.
In this IRB-approved study, participants with chronic motor complete C4-T4 SCI were included and completed informed consent. All participants underwent a dobutamine echocardiogram to assess cardiac structure and function. Dual-energy x-ray absorptiometry assessed body composition. Basal metabolic rate, respiratory quotient, and percent substrate oxidation were measured after a 12 h overnight fast using indirect calorimetry. Venipuncture was used to assess basic metabolic, lipid, and carbohydrate panels. Spearman correlations were used to evaluate relationships with an a priori alpha of 5%.
Subjects were five males and one female (age: 43.2±10.8 y, body mass index: 30.6±10.8) with SCI of 8±10.8 years duration at the C6 to the T3 levels. Left ventricle internal systolic dimension correlated with both triglycerides (ρ=-0.982, p=0.018) and very low-density lipoprotein cholesterol (VLDL; ρ=-0.982, p=0.018). Left ventricle internal diastolic dimension correlated with bone mineral content (ρ=0.953, p=0.047), high density lipoprotein cholesterol (ρ=0.956, p=0.044), low-density lipoprotein cholesterol (LDL; ρ=-0.976, p=0.024), and blood urea nitrogen (BUN; ρ=-0.975, p=0.025). Both the interventricular septum diastolic thickness and interventricular internal diastolic dimension were related to subcutaneous fat (both ρ=0.999, p=0.029). Left atrium dimension correlated with total cholesterol (TC; ρ=-0.979, p=0.021), LDL (ρ=-0.990, p=0.010), BUN (ρ=-0.958, p=0.042), and sodium (ρ=-0.962, p=0.038). Similarly, the left atrium anteroposterior dimension correlated with TC (ρ=-0.979, p=0.021), LDL (ρ=-0.990, p=0.010), BUN (ρ=-0.958, p=0.042), and sodium (ρ=-0.962, p=0.038). Aortic root diameter (ρ=1.00, p=0.004) and aortic outflow area (ρ=1.00, p=0.011) correlated with visceral fat. Functionally, maximal heart rate correlated with android mass (ρ=0.947, p=0.015), android fat (AF; ρ=0.933, p=0.021), and percent AF (ρ=0.897, p=0.039). End diastolic volume correlated with lean body mass (ρ=0.993, p=0.007), android mass (ρ=0.980, p=0.020), AF (ρ=0.980, p=0.020), percent AF (ρ=0.989, p=0.011), visceral fat (ρ=1.00, p=0.010), respiratory quotient (ρ=0.973, p=0.027), and percent fat (ρ=0.977, p=0.023) and percent carbohydrate (ρ=0.977, p=0.023) oxidation during basal metabolic rate.
Cardiac structure and function were related to body composition and metabolic profiles in high motor complete SCI.
These findings demonstrate the need to consider body composition and metabolic profile in cardiac structure and function after SCI.
