Primary hyperparathyroidism in Taiwan: clinical features and prevalence in a single-center experience.

In Taiwan, urolithiasis remains a common manifestation of primary hyperparathyroidism (PHPT). We designed this study to estimate the prevalence of PHPT in asymptomatic adults and to assess the complications already present when the disease was diagnosed. In the first phase of the study, we retrospectively reviewed 50 patients diagnosed with surgically or biochemically proven PHPT between April 1995 and April 2007. In the second phase, we reviewed the records of 4,359 asymptomatic subjects who had undergone a health examination between August 2002 and January 2007. Of the 50 patients reviewed in the first phase, hypercalcemia was the presenting complication in 33 patients (64%) followed by symptomatic recurrent solitary urolithiasis in 10 patients (20%). Of the 43 patients who underwent urologic imaging, 29 (67%) had urolithiasis and 7 (16%) had nephrocalcinosis, indicating that urinary stone disease is common. In the second phase, 28 of the 4,359 asymptomatic adults (0.64%) were found to have hypercalcemia; of these 28, 4 (0.092%) were diagnosed with PHPT. In Taiwan, PHPT remains underdiagnosed, and complications manifest in most patients upon admission. Although still relatively uncommon, screening serum calcium levels helps diagnose PHPT at an asymptomatic stage.