Youth with multiple sclerosis have low levels of fitness

Abstract

Background: Moderate and vigorous physical activity is associated with improved outcomes in youth with multiple sclerosis (MS). Physical fitness may also influence disease and health outcomes in this population. Objectives: To determine if there were differences in physical fitness between youth with MS and healthy controls (HC). To examine relationships between physical fitness, physical activity (PA) level, fatigue, depression and disease activity in youth with MS and HC. Methods: Youth with MS ( n = 19) and HC ( n = 21) completed tests establishing cardiorespiratory-fitness (VO2peak), endurance via 2-minute walk test, and musculoskeletal strength via grip strength (GS). Questionnaires determined fatigue, depression, and PA levels. Weekly PA level was determined by accelerometry. Tests of differences and correlational analyses were used to evaluate physical fitness. Results: Youth with MS had lower VO2peak ( U = 279, p < 0.0001), endurance ( t = 2.6, p = 0.02), and higher body mass index (BMI) ( t = -5.9, p = 0.001) than HC. Higher VO2peak was associated with higher moderate to vigorous PAaccelerometer in HC (Spearman-Rho = 0.5, p = 0.03), but not in youth with MS (Spearman-Rho = 0.5, p = 0.06). Lower VO2peak and GS were associated with higher disability (Spearman-Rho = -0.6, p = 0.03) and relapses in MS (Spearman-Rho = -0.52, p = 0.04). Conclusions: Youth with MS have lower levels of fitness, compared with HC. Higher levels of fitness were associated with lower disease activity and disability in youth with MS.

Six-Minute Walk Performance and Related Factors in Pediatric-Onset Multiple Sclerosis

“…It has been stated that patients with pediatric-onset multiple sclerosis participated in less physical activity (accelerometer-based activity monitoring) than their healthy peers or children with different demyelinating diseases. 9,17,[35][36][37] Patients in this study were moderately active 26 (Godin Leisure-Time Exercise Questionnaire score = 16.73) and had low participation in moderate-to-vigorous physical activity. In addition, the results of our study showed that patients with pediatric-onset multiple sclerosis (pedometer (average steps/day) = 3238.88) could not reach the recommended daily step number for their healthy peers.…”

“…34 Little is known about the exercise capacity of patients with pediatric-onset multiple sclerosis. Stephens et al 17 showed that patients with pediatric-onset multiple sclerosis had lower average maximum workload capacity (measured with cardiopulmonary exercise test) and endurance capacity (measured with a 2-minute walk test) than healthy controls. Toussaint-Duyster et al 16 also reported that patients with pediatric-onset multiple sclerosis had lower exercise capacity measured with cardiopulmonary exercise test as a maximal exercise test.…”

“…49 Knee flexor and extensor muscle strength were associated with walking performance and exercise capacity in adult patients with multiple sclerosis. [49][50][51] Stephens et al 17 reported a strong relationship between hand grip strength and higher peak workload and cardiopulmonary fitness in patients with pediatric-onset multiple sclerosis. In the current study, there was no association between functional exercise capacity and lower extremity muscle strength.…”

“…52 In studies comparing patients with pediatric-onset multiple sclerosis and other demyelinating disease groups or healthy peers, fatigue was found higher in patients with pediatric-onset multiple sclerosis. [53][54][55] Stephens et al 17 reported that lower fatigue levels were associated with increased cardiovascular fitness in patients with pediatric-onset multiple sclerosis. Similarly, fatigue in daily functions was a significant predictor of functional exercise capacity and related to walking-related fatigue in the present study.…”

“…These studies evaluated exercise capacity by using different cardiopulmonary exercise test protocols and found no relationship between exercise capacity and fatigue, quality of life, and handgrip strength. 16,17 Although cardiopulmonary exercise testing is the gold standard in assessing exercise capacity, the high cost of these systems, the requirement of trained staff, and the uncertainty of the appropriate protocol for children can limit its routine applicability in clinical environments. The 6-minute walk test (6MWT) is an inexpensive submaximal exercise test that is widely used to measure functional exercise capacity and can mimic walking in daily life in different disease groups, including multiple sclerosis.…”