Fig. 1.

Endotrophin is a collagen VI-derived cleavage product that originates in adipose tissue, secreted from adipocytes, infiltrating macrophages and local (myo)fibroblasts. It accumulates in dysfunctional adipose tissue, but can also be released into circulation. Higher levels of circulating endotrophin (>6.3 ng/ml) are associated with a better response to PPARγ agonists (i.e. TZDs), with fewer side effects. In contrast, individuals with lower endotrophin levels do not respond optimally to TZDs (in terms of fasting glucose and HbA_1c levels) and have an increased incidence of adverse side effects, such as peripheral oedema