Multivariate logistic regression revealed that Hashimoto’s thyroiditis (HT) (OR=1.786, P=0.007) and preoperative blood glucose (OR=1.319, P=0.005) was an independent risk factor, while body mass index (BMI)≥24 (OR=0.714, P=0.032),elevated preoperative PTH levels (OR=0.988, P=0.013)and male (OR=0.554, P=0.002) were protective factors. Here, PTH is linked to hematocrit.