Analyzing separately the relationships between myostatin and OSA criteria, the only significant association was detected between serum myostatin and obesity (proportion of total fat > 25%): the proportion of fat was significantly lower among patients with myostatin levels below the median (Z = 2.15; p = 0.037), but myostatin was not related to any other criterion of OSA (Table 4). The gene discussed is MSTN; the disease is obesity due to melanocortin 4 receptor deficiency.