(HealthDay News) — Lower-extremity lymphedema may be due to extreme obesity, as there appears to be a body mass index (BMI) threshold above which lymphatic flow becomes impaired, according to a letter to the editor published in the May 31 issue of the New England Journal of Medicine.
Arin K. Greene, M.D., from the Children’s Hospital Boston, and colleagues reviewed data from 15 obese patients with bilateral lower-extremity enlargement, to identify the role of obesity in lymphedema. The patients underwent lymphoscintigraphy, reported to be 100 percent specific and 92 percent sensitive for lymphedema.
The researchers identified abnormal results for five patients on lymphoscintigraphy; the results showed impaired lymphatic function consistent with lymphedema. The patients with lymphedema had a significantly greater average BMI than those without lymphedema (70.1 versus 42.0 kg/m²). All patients with a BMI higher than 59 kg/m² had lymphedema, while lymphatic function was normal for all those with a BMI below 54 kg/m².
“Our findings suggest that obesity, which affects one-third of the population in the United States, may be a cause of lower-extremity lymphedema. As BMI increases, there might be a threshold above which lymphatic flow becomes impaired,” the authors write. “Although lymphedema is typically progressive, we speculate that major weight loss (e.g., after a bariatric procedure) might reverse lymphatic insufficiency in obese patients with this condition.”