In subjects not receiving insulin therapy (n = 108), plasma leptin levels were also significantly correlated to FMD (r = 0.337, p = 0.009), but not to NMD (r = 0.224, p = 0.088), whereas insulin resistance assessed by HOMA-R was not correlated to FMD (r = −0.023, p = 0.873) or NMD (r = −0.124, p = 0.382), in the overweight group (n = 59). This evidence concerns the gene LEP and Insulin resistance.