Black patients with MS experience greater disease burden
Black patients with MS experienced a greater burden of disease compared with white patients with MS, even after adjustments for socioeconomic status, according to results published in Neurology.
“While lower socioeconomic status appears to be linked to doing worse on tests of neurologic performance in white people with MS, we do not see that for Black people with MS, at least at the single time point we examined,” study author Lana Zhovtis Ryerson, MD, a specialist in MS at NYU Langone Health in New York City and member of the American Academy of Neurology, said in a press release.
The researchers compared MS characteristics, including self-reported disability, objective evaluations of neurologic function and quantitative brain MRI measurements after adjusting for covariates, including education level, employment status or insurance as socioeconomic indicators, among Black and white participants in the MS Partners Advancing Technology Health Solutions, or MS PATHS, cohort. The MS PATHS network is a collaborative effort among 10 MS centers, seven of which are in the United States, according to the study results. They also examined within-race, neighborhood-level indicators of socioeconomic status using nine-digit ZIP codes in a subgroup of patients.
The analysis included 7,530 individuals who self-identified as white (86%) and 1,214 individuals who self-identified as Black (14%). Men comprised approximately a quarter of the participants in each cohort (Black participants, 28.2%; white participants, 26.6%). The researchers found that participants in the cohort of white patients were slightly older than participants in the Black cohort (mean age, 50.9 years vs. 47.1 years). White participants were also slightly older than Black participants at the time of symptom onset, according to the study results (33.7 years vs. 32.6 years). The researchers found that Black patients had lower levels of education and were more likely to have Medicaid for insurance or be disabled or unemployed.
Regarding MS outcomes, Black patients experienced poorer self-reported disability (1.47-fold greater odds of severe vs. mild disability; 95% CI, 1.18-1.86). They also performed worse on tests of cognitive processing speed (-5.06 fewer correct; 95% CI, -5.72 to -4.41), walking (0.66 seconds slower; 95% CI, 0.36-0.96) and manual dexterity (2.11 seconds slower; 95% CI, 1.69, 2.54).
Gray-Roncal and colleagues also found that Black patients had a greater number of brain lesions on MRI, as well as lower overall and gray matter brain volumes, including decreased thalamic (-0.77 mL; 95% CI, -0.91 to -0.64), cortical (-30.63 mL; 95% CI, -35.93 to -25.33) and deep (-1.58 mL; 95% CI, -1.92 to -1.23) gray matter volumes.
A multivariate analysis among a subset of patients “more thoroughly” examined the link between race and socioeconomic status in relation to MS-related clinical and MRI measures. That analysis demonstrated that lower median household income correlated with decreased cognitive processing and walking speeds among white patients, while a worse score on the Area Deprivation Index was tied to slower cognitive processing and manual dexterity speeds. Conversely, among Black patients, lower median income correlated only with slower manual dexterity performance, while worse Area Deprivation Index scores were not “meaningfully associated” with differences in cognitive processing, walking or manual dexterity speeds. The researchers observed “relatively consistent findings” in the overall MS PATHS cohort when using less-detailed general indicators of socioeconomic status, such as education status.
The researchers noted that the cross-sectional design of the study may have impacted the study results, adding that longitudinal studies should be performed. However, Gray-Roncal and colleagues also stated that it was “less likely” that race and the numerous health and social conditions that differ by race in the United States, which begin early in life and can extend generationally, are a “consequence” of MS or MS-related disability.
“Future studies should consider the role of unmeasured factors like systemic racism to see if they may play a role in greater disability among Black people with MS,” Zhovtis Ryerson said in the press release. “These results also reinforce the need for more diverse clinical trials and research focusing on treatment strategies specifically for Black people to identify whether certain therapies or more aggressive early treatment could help slow down disability over time.”
Reference:
American Academy of Neurology. Does socioeconomic status explain why Black people with MS have more disability? Available at: https://www.aan.com/PressRoom/Home/PressRelease/4906. Accessed July 1, 2021.