Also, we found that the difference between the two parameters (iPTH and 1-84 PTH) had high value for diagnosis of hyperparathyroidism (AUC = 0.995, P < 0.001) that in a cutoff value of 200 pg/mL could predict hyperparathyroidism with sensitivity and specificity of 100% and 86%, respectively; however, iPTH to 1-84PTH ration could not predict hyperparathyroidism (AUC = 0.370, P = 0.073). Here, PTH is linked to hyperparathyroidism.