No association of FINS (P = 0.058), 2-h postprandial plasma insulin (P = 0.257), 2-h postprandial plasma C-peptide (P = 0.146), and HOMA-IR (P = 0.170) with the presence of CAN was found (Fig. 2). Here, INS is linked to Crouzon syndrome-acanthosis nigricans syndrome.