INSR and obesity due to melanocortin 4 receptor deficiency: Additional indirect evidence also implicates insulin in obesity-induced sympathoexcitation in males: (1) icv injection of an InsR antagonist decreases BP in obese rabbits [66]; (2) in obese humans, MSNA correlates with insulin resistance and elevated insulin levels in men, but not women [7]; and (3) weight loss decreases MSNA and NE spillover in humans and this correlates with the fall in plasma insulin, regardless of glycemic status [87].