Effects of Intensive Aerobic and Muscle Endurance Exercise in Patients With Systemic Sclerosis - a Pilot Study

Overview

The hypothesis is that intensive aerobic and endurance muscle training is safe and beneficial in patients with systemic sclerosis and concurrent interstitial lung disease. The purpose of the study is to examine the effect of an eight week intensive aerobic exercise and muscle endurance training program for patients with systemic sclerosis and 50-100 % of forced vital capacity. A single subject experimental design with repeated systematic measures during a six week A-phase (baseline period) and an eight week B-phase (intervention period) was used. Physical capacity (six minute walk test), aerobic capacity (submaximal treadmill test) and muscle endurance in shoulder and hip flexion (Functional Index 2) are assessed every other week throughout the 14 week study. Activity limitation (Health Assessment Questionnaire), quality of life (Short Form 36), Raynaud, Fatigue and Global Health during the recent week (Visual Analogue Scales) are assessed at weeks 0, 6, 14. The exercise program includes aerobic exercise corresponding to 15 on the Borg RPE scale (strenuous) and muscular endurance training three times/week.

The purpose of the study is to examine the effect of an eight week intensive aerobic exercise and muscle endurance training program for patients with systemic sclerosis and 50-100 % of forced vital capacity. As systemic sclerosis is a very rare condition a Single Subject Experimental Design (SSED) was used including a 6-week non-interventional A-phase where patients are assessed systematically followed by an 8-week interventional B-phase where patients exercise three days a week with continued systematic assessments. According to the 2-standard deviation (2 SD) band analysis, statistical analysis were performed for each patient individually. Accordingly, a statistically significant change was detected if two consecutive assessments in the B-phase exceeded the 2 standard deviations (SD) of the mean of the A-phase. Patients were recruited from an ongoing study at the Karolinska University Hospital with the purpose to screen all patients with systemic sclerosis in Stockholm for cardiovascular disease. All patients meeting the inclusion criteria were invited to participate in this exercise study. Assessments: The six minute walking test was used to assess physical capacity. A submaximal treadmill test was used to estimate oxygen uptake in ml/kg x min. Muscle endurance was assessed by the Functional Index 2 registering the number of correct performed repetitions in 7 muscle groups. Pain, Raynaud's Phenomenon, fatigue and global disease impact on general well-being was assessed by the Visual Analogue scale (VAS), 0-100. Limitations in activities of daily living were assessed using the Health Assessment Questionnaire and the SF-36 was included to assess perceived health. The Exercise program: The program starts with a 10-minute warm-up session with biking at an intensity corresponding to perceived light exertion (10 on the Borg RPE, 6-20 scale). Thereafter, the load is increased to reach an intensity corresponding to perceived heavy exertion (15 on the Borg RPE scale) for an additional 15 minutes. During the last five minutes of the biking session, the loads are reduced to an intensity corresponding to light exertion. Heart rate was is recorded with a pulse watch (RS100 Polar) and peripheral saturation recorded with a heart rate oximeter (Wristox 3100 Nonin Medical). During the first weeks patients start on lower leads and increasing to the goal intensity. After the biking exercises, the participants perform repetitive dynamic muscle resistance training with the goal to achieve as many repetitions as possible in shoulder flexion and in hip flexion.