Body Mass Index and Lymphedema Morbidity: Comparison of Obese Versus Normal-Weighted Patients.

Obesity is a risk factor for the development of secondary lymphedema after axillary lymphadenectomy and radiation. The purpose of the study was to determine if obesity influences the morbidity of lymphedema in patients who have the condition.Two cohorts of patients were compared: Group 1 = normal weight, body mass index (BMI kg/m) ≤25; Group 2 = obese (BMI ≥30). Inclusion criteria were patients ≥ 21 years-old with lymphedema confirmed by lymphoscintigraphy. Covariates included age, sex, lymphedema type (primary or secondary), location, comorbidities, lymph node dissection, radiation, lymphoscintigram result, and disease duration. Outcome variables were infection, hospitalization, and degree of limb overgrowth. The cohorts were compared using the Mann-Whitney U-test, Fisher's exact test, and multivariable logistic regression.Sixty-seven patients were included: Group 1 (n=33), Group 2 (n=34). Disease duration did not differ between groups (p=0.72). Group 2 was more likely to have an infection (59%), hospitalization (47%), and moderate or severe overgrowth (79%), compared to Group 1 (18%, 6%, and 40% respectively, p<0.001). Multivariable logistic regression showed that obesity was an independent risk factor for infection (OR 7.9, 95% CI 2.5-26.3; p<0.001), hospitalization (OR 30.0, 95% CI 3.6-150.8; p<0.001), and moderate to severe limb overgrowth (OR 6.7, 95% CI 2.1-23.0; p=0.003).Obesity negatively affects patients with established lymphedema. Obese individuals are more likely to have infections, hospitalizations, and larger extremities compared to subjects with a normal BMI. Patients with lymphedema should be counseled about the negative effects of obesity on their condition.