PTH and chronic obstructive pulmonary disease: Three patients had cardiac arrhythmia, two patients had heart valve pathology, two patients had renal transplantation, one patient had a history of bypass surgery, one patient had lung pathology, one patient had liver pathology, one patient had a history of malignancy, two patients had a PTH value >100 ng/L after parathyroidectomy, and three patients follow-up period after parathyroidectomy was shorter than 6 months and one patient was excluded because of missing data.