Fatigue and its relationship with physical activity, age, and body composition in adults with cerebral palsy

AIM: The objectives of this exploratory study were (1) to describe the experience of fatigue in adults with cerebral palsy (CP) inclusive of all levels of the Gross Motor Function Classification System (GMFCS); and (2) to determine if physical activity level, sedentary time, age, or body composition can predict fatigue in adults with CP. METHOD: An observational study was conducted in an outpatient setting in Ontario, Canada. Participants included adults with CP (n=41; GMFCS levels I-V; mean age 33.7y, standard deviation [SD] 12.3y). Fatigue was measured using the Fatigue Impact and Severity Self-Assessment (FISSA) questionnaire. Habitual physical activity and sedentary time were measured using accelerometry. Body mass index (BMI) and waist circumference were reported as measures of body composition. RESULTS: The mean (SD) FISSA score for all participants was 84.5 (30.6), ranging from 54.0 (18.3) (GMFCS level I) to 93.6 (21.9) (GMFCS level V). Significant positive relationships (regression coefficient β [95% confidence intervals]) were observed between BMI and FISSA scores (1.9 [0.73-3.1]), waist circumference and FISSA scores (0.71 [0.19-1.2]), and age and FISSA scores (0.99 [0.26-1.7]). A significant negative relationship was observed between moderate-to-vigorous physical activity (MVPA) per hour and FISSA scores -6.4 [-12 to -0.83]). Backwards stepwise regression analysis revealed BMI (1.8 [0.61-2.9]) and MVPA per hour (-5.4 [-10 to -0.30]) were significant predictors of FISSA scores. INTERPRETATION: Health care providers should consider the importance of weight management and physical activity to prevent and treat fatigue in this population.