title: Prediction of permanent hypoparathyroidism after total thyroidectomy.
abstract: BACKGROUND
  Hypoparathyroidism is a common complication with thyroid surgery. The ability to predict a high risk of permanent hypoparathyroidism is important for individual prognosis and follow-up.
  
  
  METHODS
  Permanent hypoparathyroidism, defined as continuing need for vitamin D medication at 1-year post-operatively, was investigated in patients after total thyroidectomy. Blood levels of calcium and parathyroid hormone (PTH) were measured intra-operatively, the day after surgery and at 1 month post-operatively. Logistic regression analysis was performed to investigate the risk of vitamin D treatment at last follow-up, calculated as odds ratios (ORs) with 95 % confidence intervals (CIs). Patients were followed until cessation of vitamin D and/or calcium medication, until death, loss to follow-up, or end of follow-up, whichever came first.
  
  
  RESULTS
  A total of 519 patients were included. The median (range) follow-up in patients unable to cease vitamin D was 2.7 (1.2-10.3) years. The rate of permanent hypoparathyroidism was 10/519, 1.9 %. Parathyroid auto-transplantation was performed in 90/519 (17.3 %) patients. None of these developed permanent hypoparathyroidism, nor did any patient with normal PTH day 1 (>1.6 pmol/l or 15 pg/ml). The adjusted risk (OR, 95 % CI) for permanent hypoparathyroidism for log PTH on day 1 was 0.25 (0.13-0.50). In patients not auto-transplanted and with unmeasurable PTH day 1 (<0.7 pmol/l or 6.6 pg/ml), 8/42 (19.2 %) developed permanent hypoparathyroidism.
  
  
  CONCLUSIONS
  Auto-transplantation protects against permanent hypoparathyroidism, whereas low PTH day 1 is associated with high risk.
authors.affiliation: Department of Surgery, Skane University Hospital, Lund, Sweden, martin.almquist@med.lu.se.
authors.forename: M
authors.initials: M
authors.lastname: Almquist
authors.forename: P
authors.initials: P
authors.lastname: Hallgrimsson
authors.forename: E
authors.initials: E
authors.lastname: Nordenström
authors.forename: A
authors.initials: A
authors.lastname: Bergenfelz
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007011:Hypoparathyroidism / Q000097:blood* / Q000209:etiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000637:transplantation*; D010281:Parathyroid Hormone / Q000097:blood*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011379:Prognosis; D013961:Thyroid Gland; D013965:Thyroidectomy / Q000009:adverse effects*; D014182:Transplantation, Autologous; D014807:Vitamin D / Q000627:therapeutic use
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D002118:Calcium