Cardiovascular hemodynamic response to peak exercise in individuals with multiple sclerosis

Area of Science:

• Exercise Physiology
• Neurology
• Cardiovascular Health

Background:

• Multiple sclerosis (MS) is a chronic neurological condition often associated with reduced aerobic capacity (peak VO2).
• The specific hemodynamic responses to maximal exercise in individuals with MS remain largely uncharacterized.
• It is unclear whether observed hemodynamic differences in MS are attributable to the disease pathology or reduced physical fitness.

Purpose of the Study:

• To compare the hemodynamic responses during peak exercise between individuals with MS and healthy controls (CON).
• To investigate if any differences in hemodynamic responses are related to disease status or fitness levels, by matching participants for peak VO2.

Main Methods:

• A maximal incremental cycle exercise test was administered to participants with MS (n=21) and CON (n=21).
• Peak aerobic capacity (peak VO2) was assessed.
• Hemodynamic variables including heart rate (HR), stroke volume (SV), cardiac output (Q), and mean arterial pressure (MAP) were measured throughout the exercise test.

Main Results:

• No significant differences in peak VO2 were observed between the MS and CON groups.
• Hemodynamic variables (HR, SV, Q, MAP) increased similarly from baseline to peak exercise in both groups.
• A significant group-by-time interaction for HR was noted in the MS group, which was explained by age, but no such interactions were found for MAP, SV, or Q.

Conclusions:

• Individuals with and without MS, when matched for peak aerobic capacity, exhibit similar hemodynamic responses to maximal exercise.
• These findings indicate that physical fitness level is a primary determinant of hemodynamic responses during exercise in individuals with MS, rather than the disease itself.