Objective:

To investigate the association of obesity with inpatient outcomes in myasthenia gravis exacerbation and crisis using the national inpatient sample database for the years 2016-2022.

Background:

Studies have shown that myasthenia gravis and obesity are associated. However, data of class-specific associations and outcomes are limited.

Design/Methods:

We identified myasthenia gravis (G700*) and obesity (E66) using ICD-10 codes, with obesity stratified by BMI (Class I: 30–34.9, II: 35–39.9, III: ≥40). Outcomes during myasthenia gravis exacerbation hospitalization were measured such as mortality, discharge home, length of stay, and cost, use of  plasmapheresis. We used survey-weighted multivariate regression, adjusting for demographics, comorbidity index, and APR-DRG severity, with statistical significance at p<0.05.

Results:

Of ~300,000 Myasthenia Gravis (MG) hospitalizations, 64,965 were for MG exacerbation (mean age 62.8 years), with 23.8% obesity prevalence. In the exacerbation cohort, Class II obesity was associated with 52% lower in-hospital mortality (aOR 0.48, 95% CI 0.26–0.88), with an adjusted mortality rate of 2.17% versus 4.34% in non-obese patients. Patients with Class I (aOR 1.20) and Class II obesity (aOR 1.30) had higher odds of being discharged home. In contrast, Class III obesity was linked to an 8% longer length of stay (LOS) (IRR 1.08). Mortality risk increased with age (aOR 1.073 per year) and comorbidity score (aOR 1.175 per point). While obesity did not increase hospital charges, significant racial disparities were observed. Compared to White patients, Black patients had 28% lower odds of home discharge (aOR 0.72, p<0.001) and a 13% longer LOS (IRR 1.13, p<0.001). Total hospital charges were substantially higher for Hispanic ($109,509) and Asian ($114,987) patients versus White patients ($86,964, p<0.001).

Conclusions:

In MG exacerbation hospitalization