Increased Vascular Comorbidities Linked to Decreased Neuroperformance in MS

Increased vascular comorbidity burden among patients with multiple sclerosis (MS) was associated with markers neurologic dysfunction and neurodegeneration, according to study findings published in the Multiple Sclerosis Journal.

Researchers from Johns Hopkins University analyzed data from the MS Partners Advancing Technology and Health Solutions network, a partnership of 7 MS centers in the United States and 3 in Europe that is supported by Biogen. Participants (N=11,507) underwent MS neuroperformance tests and a subset had magnetic resonance imaging (MRI; n=6409) scans which were quantitatively assessed.

Scores from self-administered neuroperformance tests were normalized with Z-scores (equal to 0). Increased vascular comorbidities (³2) were associated with slower walking speed (standard deviation [SD], -0.49; 95% CI, -0.78 to -0.19; P =.001), manual dexterity speed (SD, -0.41; 95% CI, -0.57 to. -0.26; P <.0001), and cognitive processing speed (SD, -0.11; 95% CI, -0.20 to -0.02; P =.03).

Among the patients who had MRI data, 35.7% had hypertension and 11.9% had hypertension with hyperlipidemia.

The quantitative MRI showed that patients with increased vascular comorbidities had reduced brain parenchymal (mean difference [MD], -0.41%; 95% CI, -0.64% to -0.17%; P =.0007) and gray matter (MD, -0.30%; 95% CI, -0.49% to -0.10%; P =.0007) fractions. Within the gray matter, the volume of cortical gray matter was reduced (MD, -10.10; 95% CI, -15.42 to -4.78 mL; P =.002).

Stratified by individual comorbidities, patients with diabetes (n=589) had reduced walking speed (MD, -0.46; 95% CI, -0.78 to -0.15; P <.0001) and manual dexterity (MD, -0.33; 95% CI, -0.47 to -0.18; P <.0001) and patients with dyslipidemia (n=1631) had reduced manual dexterity (MD, -0.14; 95% CI, -0.24 to -0.03; P =.01) and processing speed (MD, -0.08; 95% CI, -0.14 to -0.02; P =.006). No other vascular comorbidity on its own was associated with a decline in neuroperformance.

This study may have been limited by its cross-sectional nature and the investigator’s strict definitions of comorbidities. Some patients who had well-controlled hypertension or diabetes may have been improperly stratified.

The study authors concluded that their findings “implicate vascular comorbidity burden as a potential contributor to reduced neuroperformance as well as lower brain and gray matter compartment volumes, the latter of which is particularly notable due to its likely relevance to neurodegeneration and long-term disability.”

Disclosure: Multiple authors declared affiliations with the pharmaceutical industry. Please refer to the original article for a full list of disclosures.

Reference

Fitzgerald KC, Damian A, Conway D, Mowry EM. Vascular comorbidity is associated with lower brain volumes and lower neuroperformance in a large multiple sclerosis cohort. Mult Scler. Published online January 8, 2021. doi:10.1177/1352458520984746