We found that leptin levels are clearly elevated in OSA patients (mean basal value = 12.1 ± 12.2 ug/L; men normal range: 3.8 ± 1.8 ug/L) but these levels do not correlate with OSA severity when considering confounders as obesity and fat distribution. This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.