Association between primary hyperparathyroidism and thyroid disease. Role of preoperative PTH

The association between patients with surgically treatable thyroid disease and patients affected by PHPT is not just accidental.

We report 591 patients who underwent total thyroidectomy in our center. Data, collected during the preoperative period according to our protocol for candidates to total thyroidectomy, included: type of thyroid disease, sex, age, type of surgical procedure, preoperative PTH and plasmatic calcium level. Calcium plasmatic level has been monitored at 24 hours after surgery on day 6 and monthly for 6 months.

On 591 cases, PTH above the normal range were present in 19.1% (113 patients), all asymptomatic for PHPT 30 were males (26.6%) and 83 females (73.4%), with a mean age of 62.97 +/- 12.51 years and 57.38 +/- 15.09 years ( p = 0.19). The mean preoperative PTH and calcium plasmatic level were 104.4 +/- 21.96 pg/ml and 119.7 +/- 37.93 pg/ml (p = 0.39) and 9.21 +/- 0.59 mg/dL e 9.37 +/- 0.87 mg/dl (p = 0.45) respectively. Intraoperative exploration proved a pathological parathyroid gland in 12 on 113 cases. In 9 of the 12 patients with parathyroid adenoma, hypocalcaemia developed. It resolved in 7 days for 4 patients and within 30 days for the others. No hypocalcaemia has been recorded at a 6 months follow up for the 97 considered (4 were lost at follow up).

Preoperative PTH measurement for all patients undergoing total thyroidectomy may offer a concrete tool to screen and identify the above-described category of patients, with no additional cost for further radiological investigations, because this class of patients will be submitted to bilateral cervical exploration associated with a total thyroidectomy.