Dr. Richard Prinz, a meeting attendee who is vice chair of surgery at NorthShore University HealthSystem in Evanston, Ill. rose to say he was "vexed" at the idea of abandoning postoperative PTH measurements as both calcium and PTH are used to diagnose patients, and that a substantial number of his surgical cases have high normal or borderline elevated calcium levels that are inappropriate for their PTH levels.
"These patients have similar levels, I think, to what you are describing as cured of the disease, so I find using only serum calcium as a marker of cure troubling," he added.
Dr. Carsello said their group uses 10.0 to 10.2 ng/mL as the upper limit of normal calcium.
At baseline, no significant differences were observed between patients in the elevated PTH group and the normal PTH group in preoperative calcium or creatinine, median percentage drop of intraoperative PTH at 10 minutes, or the percent undergoing minimally invasive or focused parathyroidectomy. Patients with elevated PTH, however, had larger glands resected (median 785 mg vs. 516 mg; P = .04).
Patients in the elevated PTH group also had a significantly higher body mass index than those in the normal PTH group (median 30.8 kg/m2 vs. 27.2 kg/m2; P less than .0001), and were more likely to be black (19% vs. 6%).
Dr. Carsello and Dr. Sippel reported no conflicts of interest.