PTH and Hypocalcemia: After adjusting for PTH-D1 level, duration of operation and concomitant autoimmune thyroiditis, the PTH-SC level [β coefficient = 0.912, odds ratio (OR) 2.488 (95 % CI 1.520–4.065), p < 0.001] and parathyroid autotransplantation (β coefficient = 1.173, OR 3.231, 95 % CI 1.215–8.597, p = 0.019) were the two independent factors for hypocalcemia.