番茄社区

Obesity may contribute to the development of lymphedema, a small study showed.

Among 15 obese patients with enlargement of the legs, the average body mass index was significantly greater for those with confirmed lymphedema (70.1 versus 42.0 kg/m², P<0.001), according to Arin Greene, MD, of Children's Hospital Boston, and colleagues.

"Our findings suggest that obesity ... may be a cause of lower-extremity lymphedema," they wrote in a letter to the editor in the New England Journal of Medicine.

"As the amount of adipose tissue increases in the lower extremity, lymphatic vessels may become dysfunctional (possibly because of compression or inflammation), thereby reducing proximal lymphatic flow," they explained.

"Alternatively, elevated production of lymph from an enlarging limb may overwhelm the capacity of a normal lymphatic system to remove the fluid from the extremity," they continued. "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."

All of the patients in the study were referred for bilateral enlargement of the lower extremities; 12 were women, the mean age was 58, and the mean BMI was 51.4 kg/m². None of the patients had a history of primary (idiopathic) lymphedema, inguinal lymphadenectomy or radiation, or ulceration of a lower extremity.

All of the patients underwent evaluation with lymphoscintigraphy. Five showed abnormal lymphatic draining consistent with lymphedema and the rest had normal results.

The BMI was greater than 59 kg/m² for all of the patients with lymphedema and less than 54 kg/m² for all of those with normal lymphatic function.

"As BMI increases, there might be a threshold above which lymphatic flow becomes impaired," Greene and colleagues wrote. "Proximal transport of lymphatic fluid from the extremity is dependent on the function of the lymphatic vasculature (clearance) and the volume of lymph produced by the tissues (load)."

Sex and age did not differ based on lymphedema status.