Physical Activity Level and Adiposity in Community-dwelling People with Spinal Cord Injury

Abstract

Obesity is a negative sequelae after spinal cord injury (SCI), leading to increased health risk and the eventual onset of cardiovascular disease. Individuals with SCI have been characterised as extremely sedentary, and the daily lifestyle of a wheelchair-bound person is not sufficient to avoid weight/adiposity gain. PURPOSE: This study compared EE, physical activity levels (PA) and adiposity in people with SCI. We also sought to determine whether wheelchair users who self-reported as "regular exercisers" showed differences in EE, PA and amount of body fat when compared to sedentary individuals with SCI. METHODS: Ten individuals with SCI were sub-divided into: (i) a group of wheelchair users engaged in "regular physical activity" for a minimum of 150 min of exercise per week during the last 6 mo (EXE; N=5) and; (ii) a group of people with SCI not undertaking any regular physical activity/exercise (SED; N=5). Total daily energy expenditure (TDEE) was measured by doubly-labeled water (DLW), resting metabolic rate (RMR) was assessed by indirect calorimetry, PA was calculated as TDEE/RMR, and fat mass estimated from total body water, determined by 18O dilution. RESULTS: Although not significant, TDEE and BMR, adjusted for body mass, were lower in SED compared to EXE (SED TDEE = 122±20 kJ·kg-1·d-1 versus EXE TDEE = 128±15 kJ·kg-1·d-1; SED BMR = 78±11 kJ·kg-1·d-1 versus EXE BMR = 93±10 kJ·kg-1·d-1). PA for SED was 1.4±0.2 and for EXE was 1.4±0.1. The percentage of body fat was significantly higher in the sedentary individuals than in physically active people (40.5±2.9% and 28.3±9.4%; P<0.05). CONCLUSION: Although EXE was engaged in at least 150 minutes of exercise weekly, this group showed a non-significantly higher TDEE and BMR, yet similar PAL. In addition, despite the significantly reduced percentage of body fat in the physically active individuals compared to sedentary SCI, both groups are considered 'obese', based on fat mass cut-offs of >22% (men 18+ yr) or > 28% (men 41 to 60 yr). These findings suggest that wheelchair-bound people with SCI need to engage in exercises at higher intensity and/or frequency in order to avoid weight gain increased body adiposity.