COBL and Insulin resistance: In addition to that, MKX but not COBL expression showed an inverse and BMI SDS-independent association with serum leptin levels (Figure 7d; Radjusted = −0.168, padjusted = 0.028) and the insulin resistance marker HOMA-IR (Figure 7e; Radjusted = −0.211, padjusted = 0.003).