Study: Younger age of disease onset for Asian Americans with MS

People of Asian descent tend to be younger than white people when they first exhibit symptoms of multiple sclerosis (MS), a U.S. study reports.

Asians also tended to be younger at the time of their diagnosis. No differences were found in demographics or disease characteristics between Asian patients born in the U.S. and those born in Asia and living in the U.S.

The researchers suggest that clinicians may want to tailor their approach to account for the younger average age of Asians when they are diagnosed. “Further understanding of this population would allow for more personalized and customized care,” they wrote. The study, “Earlier age of onset of multiple sclerosis in Asian patients in a Northeastern United States cohort,” was published in Multiple Sclerosis and Related Disorders.

Ancestry is believed to influence the disease’s course. The researchers noted that “there has been significant effort in Asian countries and in the United Kingdom to characterize the clinical course of Asian MS patients,” but few studies have been done in the U.S. Here, researchers examined the clinical records of almost 7,000 MS patients using data over two decades (2002 to 2023) of clinical care at the Brigham and Women’s MS Center in Boston. All the patients completed standard neurological assessments and demographic surveys, which included questions about racial and ethnic self-identification.

Among 6,799 people who identified as white, the first symptoms of MS appeared when they were an average age of 34.5. The 119 self-identified Asian people in the group had their first symptoms at an average age of 31.1.

This gap widened at the mean age of diagnosis, 37.6 for whites and 33.2 for Asians. This means that not only did Asian patients begin having symptoms earlier in life, they also had a shorter gap between the start of their symptoms and receiving a diagnosis. Moreover, on average, less time passed between symptom onset and starting disease-modifying therapy in Asians — 3.3 years, compared with 6.4 years for white people.

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Explaining the differences between whites, Asian Americans

The disparities could be explained by differences in social determinants of health, including education level, language familiarity, and wealth, between the groups. They may also reflect differences in genetics and environment.

No other significant differences in clinical disease characteristics were found between the groups.

Most participants in both groups were diagnosed with relapsing-remitting MS, with sensory symptoms being the most common ones at disease onset. Asian participants tended to have lower disability levels on their first visit to the clinic, but this was accounted for by their shorter average disease duration.

“Accounting for disease duration showed no differences in disability between whites and Asians,” wrote the researchers, who also compared U.S.-born Asians with MS to patients born in Asia to better understand the relative influence of genetics and environment. No significant differences emerged, but the analysis was relatively limited as about a third of the Asian group analyzed didn’t indicate their country of origin.

“In our limited sample size, we did not find major significant differences between Asian patients born within the U.S. or those who immigrated to the U.S. from other countries,” the researchers wrote.

The study is largely consistent with a 2023 U.S.-based study that indicated Asian MS patients in the U.S. seem to be younger at symptom onset and diagnosis than non-Asians, despite some limitations. The scientists suggest that clinical care for MS could be customized to take these differences into account, but noted that more research  is needed to “explore environmental and genetic factors to better understand the underlying pathogenic mechanisms of this finding.”