KNG1 and obesity due to melanocortin 4 receptor deficiency: Our results support the role of LDL-c/HDL-c ratio in determining endothelial function in obesity by demonstrating a significant negative association between LDL-c/HDL-c and pEC50 for BK in mesenteric small arteries from obese subjects but also by showing a significant impairment of endothelial vasodilation in arteries from obese subjects with LDL-c/HDL-c >2 (more than two times more LDL-c than HDL-c) with respect to those obtained from obese subjects with LDL-c/HDL-c below this score.