There was no significant independent association of POD with the preoperative BChE activity (OR = 0.971 (95% CI: 0.939 to 1.004), p = 0.086), age (OR = 1.027 (95%CI: 0.998 to 1.057), p = 0.065) or type 2 diabetes mellitus (OR = 1.508 (95%CI: 0.800 to 2.842), p = 0.204). Here, BCHE is linked to diabetes mellitus.