Effects of Aerobic Capacity on Arterial Stiffness in Individuals with Multiple Sclerosis

Abstract

INTRODUCTIONIndividuals with Multiple Sclerosis (MS) exhibit a greater risk of cardiovascular disease than individuals without MS, and increased arterial stiffness is one possible risk factor. Higher aerobic capacity has been associated with lower arterial stiffness in healthy individuals and helps explain lower risk profiles. Individuals with MS in general have low aerobic capacities and the effect of MS may abolish expected relationships between fitness and arterial stiffness.PURPOSETo determine the relationship between peak oxygen consumption (VO2peak) and carotid arterial stiffness in individuals with MS.METHODSThirteen individuals with MS (43 ± 9 yrs; 25.0 ± 3.7 kg/m2) underwent an individualized incremental treadmill test to volitional exhaustion with measures of oxygen uptake. Carotid arterial stiffness was measured by ultrasonography prior to the treadmill test, and echo‐tracking software was used to calculate the β‐stiffness index, pressure‐strain elasticity modulus (Ep) and arterial compliance (AC). Bivariate correlations were implemented to examine the linear relationship between VO2peak and carotid arterial stiffness. Partial correlations were performed to control for body weight.RESULTSNegative correlations were observed between absolute VO2peak and β‐stiffness index, (p<0.05) and Ep (p<0.05), whereas a positive correlation was found with AC (p<0.05). However, the significance between VO2peak and carotid stiffness variables was eliminated when controlling for body weight.CONCLUSIONThe findings suggest that aerobic capacity is negatively associated with carotid arterial stiffness and positively associated with arterial compliance, while body weight influences these relationships in an expected manner. Thus, aerobic training and/or weight loss might be an effective treatment to decrease arterial stiffness and consequently risk of cardiovascular disease in a population with MS. Arterial Stiffness Variables Absolute VO2peak Bivariate Correlation Absolute VO2peak Partial Correlation β‐stiffness index −0.604* −0.421 Ep (kPa) −0.682* −0.529 AC (mm22/kPa) 0.672* 0.508 Significant correlation: p<0.05