OBJECTIVES: Myasthenia Gravis (MG) is an autoimmune condition involving antibodies targeting neuromuscular junctions, resulting in fatigue-induced muscle weakness. The research aims to assess the impact of physical activity on patients with MG, recognizing the evidence gap.

METHODS: The Myasthenia Gravis Foundation of America (MGFA) Global MG Patient Registry (MGFAPR) is an online longitudinal patient-reported registry (started in 2013) hosted on the Health Storylines platform (since 2022). To conduct a cross-sectional retrospective study, enrollment surveys collected from MGFAPR between July 2013 and March 2022 were utilized. Participants were 18 years of age and above, with a self-reported MG diagnosis, excluding the participants with incomplete responses to physical activity. Descriptive statistics and two logistic regression models were run to explore the association of physical exercise to MG-ADL score and exacerbations individually controlling for gender, age at enrollment, MG-QoL-15r, income, and BMI.

RESULTS: The study included 3,550 MG patients: 42.7% in no-exercise (NE), 36.5% in moderate exercise (ME), and 21.81% in high-level exercise (HE) groups. HE showed lower MG-ADL (HE:5.08; ME:6.05; NE:7.7, p<.001), MG-QoL-15r (10.47; 13.06; 17.26, p<.001), BMI (28.22; 30.4; 32.54, p<.001), depression/anxiety prevalence (28%; 41%; 51%, p<.001) and higher income (69,978$; 64,957$; 56,831$, p<.001) compared to ME and NE. HE and ME had a lower risk of having an MG-ADL score of over 5 in comparison to NE (OR 0.87, 95% CI 0.7-1.1; OR 0.89, 95% CI 0.7-1.2, respectively) although not statistically significant. Additionally, HE and ME had a statistically significant lower risk of exacerbation in comparison to NE (OR 0.67, 95% CI 0.5-0.8; OR 0.76, 95% CI 0.65%-0.9%, respectively).

CONCLUSIONS: This study shows that physical activity may be positively associated with MG disease symptoms. Further research including a longitudinal study is warranted to understand the causal effects of physical exercise on MG disease outcomes.