GPT and Crouzon syndrome-acanthosis nigricans syndrome: Upper ALT and gamma-glutamyl transferase (GGT) tertiles (T3 vs. T1-2: odds ratio [OR], 95% confidence interval [CI], 2.05 [1.20, 3.48], and 2.99 [1.61, 5.58], respectively) predicted CAN development (23%, n = 24) independent of HbA1c and diabetes duration.