Physical Activity and Body Composition Among Ambulatory Individuals With Multiple Sclerosis

Individuals with multiple sclerosis (MS) engage in less physical activity than the general population. This level of inactivity may increase a person's risk of being overweight and obese. The relationship between physical activity and body composition is examined among 34 ambulatory adults with a definite diagnosis of MS. Participants wore pedometers and accelerometers, objective measures of physical activity, for 7 days; completed a self-report measure of physical activity; and underwent various measurements of body composition, including body mass index (BMI), waist circumference, and relative body fat by dual energy X-ray absorptiometry (DXA). Statistically significant negative correlations were found between physical activity levels and measures of body fatness, and the correlations were strong between the objective measures of physical activity and DXA measures of body composition. The correlations were moderate between the self-report measure of physical activity and less precise measures of body composition. Our findings suggest that inactivity plays an important role in body fatness among people with MS, and subjective measures of physical activity and less precise measures of body fatness, such as BMI, may underestimate the strength of the relationship between physical activity and risk for obesity in the MS population.