A lower body mass index (BMI) at the onset of neuromyelitis optica spectrum disorder (NMOSD) seems to be associated with less frequent relapses and higher treatment efficacy, a new study published in Annals of Clinical and Translational Neurology found. However, it also seems to also be associated with poor prognosis, including a higher risk of permanent disability.

These findings suggested that BMI at onset could be valuable in identifying high-risk patients and could predict the outcome,” the authors of the study said. 

To assess the potential link between body mass index at disease onset, clinical features, and prognosis in NMOSD, the team led by Hongyu Zhou from the department of neurology, West China Hospital, Sichuan University, Chengdu, China, conducted a retrospective cohort study in 246 patients with NMOSD between January 2015 and January 2022. Of these, the majority (78%) were anti-aquaporin 4 antibody-positive.

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The researchers divided the patients into 3 groups based on their BMI at disease onset—low BMI (36 patients), normal BMI (133 patients), and high BMI (77 patients).

Read more about the prognosis of NMOSD

The patients had a total of 799 NMOSD attacks and the mean age of disease onset was 40 years. The median follow-up time was around 4 years.

Statistical analysis revealed that BMI at disease onset correlated with the risk of relapse, severe attack, visual disability, and overall disability.

The results also showed that the onset and relapse of area postrema syndrome were less frequent in patients who had a normal BMI. Moreover, the annual relapse rate following immunosuppressive therapy was significantly lower among patients who had a low BMI at disease onset. 

However, the researchers stressed that the predictive value of BMI was limited in their study since only BMI at the first attack was recorded. “Therefore, prospective cohort studies are required to evaluate the effects of dynamic BMI on disease course and prognosis in patients with NMOSD,” they said.


Luo W, Wang X, Kong L, Chen H, Shi Z, Zhou H. Initial BMI effects on clinical presentation and prognosis in neuromyelitis optica spectrum disorder. Ann Clin Transl Neurol. Published online July 26, 2023. doi:10.1002/acn3.51857