RESUMO
PURPOSE: Subjects with spinal cord injury (SCI) have been reported to present impaired left ventricular (LV) diastolic function in comparison with able-bodied (AB) ones. The present study investigated the effect of regular physical activity on the cardiac structure and function of SCI subjects. METHODS: Fifty-eight SCI men (29 sedentary [SCI-S] and 29 athletes [SCI-A]) and 29 AB men were cross-sectionally evaluated by clinical, laboratory, hemodynamic, and echocardiographic analysis. All enrolled subjects were normotensive, nondiabetic, nonsmoker, and normolipemic, and the studied groups presented similar age and body mass index. RESULTS: SCI-S presented similar LV structural and systolic parameters but higher E/Em (8.0 ± 0.5) and lower Em/Am (1.18 ± 0.09) ratios than SCI-A and AB (E/Em = 6.4 ± 0.3 and 5.9 ± 0.3, respectively; Em/Am = 1.57 ± 0.12 and 1.63 ± 0.08, respectively; all P < 0.05 compared with SCI-S). Analysis of SCI individuals according to injury level revealed that tetraplegic athletes had similar features compared with sedentary tetraplegic subjects, except for higher Em (10.9 ± 0.6 vs 8.6 ± 0.7 cm s, P < 0.05) and lower E/Em ratio (6.3 ± 0.4 vs 8.8 ± 0.8, P < 0.05), whereas paraplegic athletes had similar features compared with sedentary paraplegic individuals, except for higher LV end-diastolic diameter (49.4 ± 1.4 vs 45.0 ± 1.0 mm, P < 0.05) and Em/Am ratio (1.69 ± 0.20 vs 1.19 ± 0.08, P < 0.05) and lower LV relative wall thickness (0.330 ± 0.012 vs 0.369 ± 0.010, P < 0.05) and heart rate (67.1 ± 4.2 vs 81.9 ± 2.8 bpm, P < 0.05). CONCLUSION: Regular physical activity is associated with improved LV diastolic function in SCI subjects and might exert distinct cardiac structural effects in tetraplegic and paraplegic subjects.
Assuntos
Diástole/fisiologia , Exercício Físico/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Estudos Transversais , Ventrículos do Coração/diagnóstico por imagem , Hemodinâmica , Humanos , Masculino , Paraplegia/fisiopatologia , Quadriplegia/fisiopatologia , Comportamento Sedentário , Ultrassonografia , Disfunção Ventricular Esquerda/diagnóstico por imagemRESUMO
OBJECTIVE: Previous reports have indicated that subjects with chronic spinal cord injury (SCI) exhibit increased cardiovascular risk compared to able-bodied individuals. This study investigated the relationship between plasmatic oxidized low-density lipoprotein (OxLDL), matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) levels and vascular remodeling in SCI subjects and the role of physical activity in this regard. METHODS: We studied 42 men with chronic (≥2 years) SCI [18 sedentary (S-SCI) and 24 physically active (PA-SCI)] and 16 able-bodied men by clinical, anthropometric, laboratory, and carotid intima-media thickness (IMT) analysis. All enrolled subjects were normotensive, non-diabetics, non-smokers and normolipemic. Plasmatic OxLDL, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 levels were determined by enzyme-linked immunosorbent assay. RESULTS: Carotid IMT, IMT/diameter ratio and OxLDL levels of PA-SCI and able-bodied subjects were statistically similar. Conversely, S-SCI subjects exhibited higher IMT, IMT/diameter ratio and OxLDL levels compared to PA-SCI (p < 0.01, p < 0.001 and p = 0.01, respectively) and able-bodied (p < 0.001 for all) individuals. Results of bivariate correlation analysis including all injured subjects showed that carotid IMT and IMT/diameter ratio only correlated with OxLDL, MMP-8 and MMP-8/TIMP-1 ratio. Further stepwise regression analysis adjusted for the presence or not of physical activity and age showed that OxLDL was associated with carotid IMT and IMT/diameter ratio, while MMP-8 was associated with IMT/diameter ratio in SCI individuals. CONCLUSIONS: Plasmatic OxLDL and MMP-8 levels are associated with carotid atherosclerosis and there is an interaction among physical inactivity, atherosclerosis and OxLDL in SCI individuals.