INS and obesity due to melanocortin 4 receptor deficiency: Peak GH secretion after stimulation was inversely associated with fasting insulin (R = −0.650, P = .012), HOMA-IR (R = −0.846, P = .001), total cholesterol (R = −0.532, P = .034), and LDL cholesterol (R = −0.692, P = .006) and positively associated with HDL cholesterol (R = 0.561, P = .037).These data strongly suggest a role for insulin resistance in the decreased GH secretion of obesity and that the blunted GH secretion of central obesity could be the pituitary expression of the metabolic syndrome.