Does Obesity Increase the Risk of Developing Myasthenia Gravis?

Myasthenia gravis is a rare autoimmune disease that affects the junctions between nerves and muscles. It is characterized by fluctuating muscle weakness and difficulty repeating certain movements. While genetic factors are known to promote its onset, environmental causes remain less clear. A recent study conducted in South Korea on more than 3.9 million adults followed over ten years provides new insights into the role of obesity in this disease.

The results show that people suffering from obesity have an increased risk of developing myasthenia gravis compared to those with a normal weight. Among the participants, those classified in the severe obesity category were nearly twice as likely to receive a diagnosis of myasthenia gravis. Even moderate obesity significantly increased this risk. Conversely, underweight men also showed particular vulnerability, with a risk more than twice the average.

Obesity is known to create an inflammatory environment in the body. It disrupts the balance of immune cells, thereby promoting the emergence of autoimmune diseases. In the case of myasthenia gravis, the mechanisms involved may include increased production of pro-inflammatory substances by fat cells. These substances weaken the natural defenses that normally prevent the immune system from attacking the body’s own tissues. Additionally, certain deficiencies common in obese individuals, such as low vitamin D levels, could worsen this immune imbalance.

The study also highlights that the risk increases with the duration of obesity, suggesting a cumulative effect over the long term. These observations align with those made for other autoimmune diseases, such as rheumatoid arthritis or multiple sclerosis, where excess weight is already recognized as a risk factor.

These findings open avenues for better understanding and preventing myasthenia gravis. They suggest that weight management could play a role in reducing risks, although further research is needed to confirm this link and explore its precise mechanisms.

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Official Study Source

DOI: https://doi.org/10.1007/s13760-026-03022-y

Title: Association between obesity and subsequent risk of myasthenia gravis: a nationwide population-based cohort study

Journal: Acta Neurologica Belgica

Publisher: Springer Science and Business Media LLC

Authors: Soonwook Kwon; Ye Bin Park; Kyung-Do Han; Yeon Hak Chung; Eun Bin Cho; Dong Wook Shin; Ju-Hong Min