Adipose tissue biology and effect of weight loss in women with lipedema

Lipedema is a lipodystrophic disease that is typically characterized by a marked increase in lower-body subcutaneous adipose tissue that is purported to have increased inflammation and fibrosis, impaired microvascular/lymphatic circulation and to be resistant to reduction by weight loss therapy. However, these outcomes have not been adequately studied. We evaluated body composition, insulin sensitivity, metabolic health and adipose tissue biology in women with obesity and lipedema (Obese-LIP) before and after moderate (~9%) diet-induced weight loss. At baseline, people with Obese-LIP had ~23% greater leg fat mass, ~11% lower android-to-gynoid ratio and ~48% greater insulin sensitivity (all P<0.05) than women matched on age, BMI and whole-body adiposity. In Obese-LIP, macrophage content and expression of genes involved in inflammation and fibrosis were greater, whereas lymph/angiogenesis-related genes were lower in thigh than abdominal subcutaneous adipose tissue. Weight loss improved insulin sensitivity and decreased total fat mass, with similar relative reductions in abdominal and leg fat masses, but without changes in markers of inflammation and fibrosis. These results demonstrate that affected adipose tissue in women with lipedema is characterized by increased inflammation and fibrogenesis, and alterations in lymphatic and vascular biology. Moderate diet-induced weight loss improves metabolic function and decreases lower-body adipose tissue mass.