MMP9 and obesity due to melanocortin 4 receptor deficiency: As shown in Fig. 4, MMP-9 levels were negatively correlated with basal CVC in people with obesity (r = − 0.47, p = 0.004, Fig. 4c), however, no correlation was found among non-obese and overweight people (r = 0.28, p = 0.16; r = 0.65, p = 0.15, Fig. 4a,b, respectively).