Low-Grade Systemic Inflammation and Leptin Levels Were Improved by Arm Cranking Exercise in Adults With Chronic Spinal Cord Injury

Abstract

ObjectiveTo ascertain the effect of arm cranking exercise on improving plasma levels of inflammatory cytokines and adipokines in untrained adults with chronic spinal cord injury (SCI). DesignLongitudinal study. SettingCommunity-based supervised intervention. ParticipantsMen (N=17) with complete SCI at or below T5 volunteered for this study. Participants were randomly allocated to the intervention (n=9) or control group (n=8) using a concealed method. InterventionA 12-week arm cranking exercise program of 3 sessions per week consisted of warm-up (10–15min), arm crank (20–30min; increasing 2min and 30s every 3wk) at a moderate work intensity of 50% to 65% of heart rate reserve (starting at 50% and increasing 5% every 3wk), and cool-down (5–10min). Main Outcome MeasuresPlasma levels of leptin, adiponectin, plasminogen activator inhibitor-1, tumor necrosis factor-alpha, and interleukin-6 were determined. Furthermore, physical fitness (maximum oxygen consumption [V˙O2max]) and body composition (anthropometric index, waist circumference, and body mass index) were also assessed. ResultsPlasma levels of leptin, tumor necrosis factor-alpha, and interleukin-6 were significantly decreased after the completion of the training program. Similarly, the anthropometric index and waist circumference were diminished too. A moderate correlation was found between leptin and the anthropometric index. Finally, V˙O2max was significantly increased, suggesting an improvement of physical fitness in the intervention group. No changes were found in the control group. ConclusionsArm cranking exercise improved low-grade systemic inflammation by decreasing plasma levels of inflammatory cytokines. Furthermore, it also reduced plasma leptin levels. Long-term, well-conducted studies are still required to determine whether these changes may improve clinical outcomes of adults with chronic SCI.