Influence of body mass index on postoperative complications after thymectomy in myasthenia gravis patients

OBJECTIVES: It is not clear whether being overweight or obese influences postoperative complications in myasthenia gravis (MG) patients. We retrospectively investigated an association between body mass index (BMI) and postoperative complications in MG. MATERIALS AND METHODS: Fifty-nine MG patients who had undergone transsternal thymectomy were classified as low or high BMI based on the criteria for Asian-Pacific populations. An association between BMI and complications was analyzed. RESULTS: MG patients with high BMI had significantly higher rates of major adverse complications (P = 0.033), postoperative respiratory failure (P = 0.045), and longer postoperative hospitalization (P = 0.005). The optimal cutoff value of BMI for postoperative respiratory failure was 23.3 kg/m(2), with a sensitivity of 75.0% and a specificity of 64.7% (P = 0.046). CONCLUSIONS: MG patients with a BMI indicating overweight or obesity have a higher risk of postoperative complications after thymectomy. Thus, close monitoring must be performed when surgery is necessary.