Endocrine Abstracts (2009) 20 P255

Preoperative parathyroid hormone levels are correlated with parathyroid adenoma volume, bone mineral density but not serum calcium levels

Sinem Kiyici1, Soner Cander1, Ozen Oz Gul1, Deniz Sigirli2, Oguz Kaan Unal1, Ozlem Saraydaroglu3, Canan Ersoy1, Erdinc Erturk1, Ercan Tuncel1 & Sazi Imamoglu1

1Department of Endocrinology and Metabolism, Medical Faculty, Uludag University, Bursa, Turkey; 2Department of Bio-Statistics, Medical Faculty, Uludag University, Bursa, Turkey; 3Department of Pathology, Medical Faculty, Uludag University, Bursa, Turkey.

The aim of this study was to determine the relationship between biochemical parameters, parathyroid adenoma volume, and bone mineral density with respect to intact parathyroid hormone (iPTH) levels in patients with primary hyperparathyroidism. Data were collected retrospectively from patients with primary hyperparathyroidism who were diagnosed and followed-up at our clinic between 2004 and 2008. Forty-eight (female/male=42/6) patients with a mean age of 52.8±13.1 (range 23–75) years were enrolled into the study. Bone pain was the most common presenting feature in 41.7% of patients, while 45.8% of patients were asymptomatic. The mean serum calcium and iPTH concentrations were 11.5±2.2 mg/dl and 657.1±682.0 pg/ml, respectively. The mean total Z/T scores of DEXA scan at femur and lumbal spine were −0.4±1.6/−1.0±1.7 and −1.4±1.6/−2.2±1.5, respectively. Parathyroidectomy was performed in 39 patients while nine patients were observed with medical treatment. The sensitivity of ultrasound and Tc-99 m sestamibi scintigraphy for parathyroid adenoma localization was 31 and 79%, respectively. Preoperative iPTH levels were correlated with serum phosphate (r=−0.412, P=0.005), alkaline phosphates (r=0.698, P=0.0001), femur (r=−0.402, P=0.020) and lumbal spine total Z scores (r=−0.441, P=0.013) whereas parathyroid adenoma volume was correlated with iPTH (r=0.367, P=0.036) and alkaline phosphates (r=0.570, P=0.001). There was no correlation between iPTH, serum calcium levels and total T scores at femur and lumbal spine. Serum 25-hydroxyvitamin D (25-OHD) levels were below <10 ng/ml in 16 patients. After excluding patients with 25-OHD insufficiency there was still no correlation between serum iPTH and calcium levels. Parathyroid adenoma volume, serum iPTH and calcium levels were also not different between patients with and without 25-OHD insufficiency.

In conclusion, these results suggest that iPTH levels may be useful to predict parathyroid adenoma volume and it is also well correlated with femur and lumbal spine total Z scores.