Elevated parathyroid hormone after parathyroidectomy delays symptom improvement

Background Curative parathyroidectomy for primary hyperparathyroidism (PHPT) resolves various nonspecific symptoms related to the disease. Between 8% and 40% of patients with normocalcemia after parathyroidectomy have persistently elevated parathyroid hormone (ePTH) levels at follow-up. We investigated whether ePTH in the early postoperative period was associated with the timing of symptom improvement. Materials and methods This prospective study included adult patients with PHPT who underwent curative parathyroidectomy from November 2011 to September 2012. Biochemical testing at 2 wk postoperatively identified ePTH (defined as PTH > 72 pg/mL) versus normal PTH (nPTH). A questionnaire administered pre- and post-operatively at 6 wk and 6 mo asked patients to rate the frequency of 18 symptoms of PHPT on a five-point Likert scale. Student t-tests were used to compare pre- with postoperative changes in scores for individual symptoms. Results Of 194 patients who underwent parathyroidectomy, 129 (66%) participated in the study. Preoperatively, all patients were symptomatic, with a mean of 13 ± 4 symptoms. Two weeks postoperatively, 20 patients (16%) had ePTH. The percentage of patients with postoperative improvement for individual symptoms was compared between groups. At the early time point (6 wk), the ePTH group showed less improvement in 14 of 18 symptoms. This difference reached statistical significance for four symptoms: anxiety, constipation, thirst, and polyuria. By the 6-mo time point, these differences had resolved, and symptom improvement was similar between groups. Conclusions ePTH after curative parathyroidectomy may result in a delay in symptom improvement 6 wk postoperatively; however, this difference resolves in 6 mo.