Multiple Sclerosis Patients Do not Show Changes in Wave Intensity Analysis Following Home‐Based Exercise

Abstract

Physical inactivity and a host of other behavioral and lifestyle characteristics result in increased prevalence rates of cardiovascular disease (CVD) among multiple sclerosis (MS) patients. Non‐invasive assessment techniques can quantify arterial dysfunction, and have been shown to detect positive arterial responses to aerobic exercise training. Wave intensity analysis (WI), an ultrasound measurement which serves as a surrogate measure of ventricular‐arterial interaction, is one such non‐invasive methodology. Our purpose was to determine if WI changes as a result of home‐based aerobic exercise in MS patients. Participants completed either a 3 month home‐based aerobic exercise (N=26, 49±11 years) or stretching (N=22, 43±13 years) intervention. Exercisers completed 3 days per week of moderate intensity cycling (progressing from 40% to 60% of aerobic capacity and from 10 to 30 minutes), and stretchers completed 3 days per week of a whole body routine (progressing from 5 to 20 stretches). Ultrasound assessments of the carotid artery were performed after 15 minutes of supine rest at baseline and after 12 weeks. Carotid blood pressures were measured with applanation tonometry and entered into the ultrasound. P < 0.05 for all analyses. Group differences at baseline were found for carotid artery diameter difference, WD1, and velocity range. No Time*Group interactions were found for any WI variables. See table 1 for carotid artery WI analysis results. Our data suggest that 3 months of home‐based aerobic exercise at moderate intensity is insufficient to impact wave intensity in multiple sclerosis patients. Since WI is able to assess ventricular‐arterial interaction at a specific point in the arterial tree, future studies in this population should consider assessing WI in locations different than the carotid artery. Additionally, effects on WI of increased volume of aerobic exercise have yet to be explored in this population.Support or Funding InformationThis project was supported by the National Multiple Sclerosis Society RG 4702A1/2. Data are presented as Mean ± SD. Baseline 12 Weeks Stretching (N=22) Exercise (N=26) Stretching (N=22) Exercise (N=26) Diameter Δ (cm)# 0.50 ± 0.11 0.41 ± 0.14 0.49 ± 0.13 0.43 ± 0.15 1st (w1) 9152.3 ± 5901.4 7431.3 ± 4925.5 10500.0 ± 8296.1 6975.8 ± 6361.3 Wd1 (m/s3)# 19.7 ± 16.1 12.5 ± 9.7 18.7 ± 13.6 11.7 ± 11.6 2nd (w2) 552.3 ± 648.9 1275.0 ± 1246.2 940.9 ± 970.6 1162.5 ± 1203.0 Wd2 (m/s3) 1.0 ± 1.3 1.9 ± 2.0 1.5 ± 1.5 1.8 ± 1.9 Velocity Range (cm/s)# 44.5 ± 16.9 35.3 ± 13.7 48.7 ± 14.5 41.0 ± 14.5 * Interaction (Time*Group). Difference between Stretching and Exercise at baseline.