A Pilot Study to Examine the Management of Asymptomatic Hyperparathyroidism in Japanese Patients in Accordance with the Guidelines for Asymptomatic PHPT Proposed at the Third International Workshop in 2008

Objective The treatment for asymptomatic primary hyperparathyroidism (PHPT) remains controversial. In 2008, the Third International Workshop on the Management of Asymptomatic PHPT proposed a set of guidelines for the management of asymptomatic PHPT. We therefore evaluated the application of the Workshop recommendations in Japanese patients with asymptomatic PHPT. Methods We analyzed each parameter of the guidelines in 87 Japanese patients with asymptomatic PHPT who underwent methoxy-isobutyl-isonitrile (MIBI) scintigraphy. Results Fewer than 10% of the patients were less than 50 years of age. The bone mineral density T-score was below -2.5 SD in 20 women (46.5% of all women analyzed) and in none of the men. The eGFR was <60 mL/min/1.73 m(2) in 17 patients. A majority of patients (43) satisfied only one parameter, while 25 patients satisfied none of the parameters. Furthermore, the MIBI-positive and surgically treated patients tended to satisfy a larger number of the parameters. The Workshop criteria and levels of PTH, daily Ca excretion, serum ALP and 1,25(OH)2 Vitamin D were further analyzed in relation to the findings of MIBI scans, and almost all of the parameters were found to be significantly correlated with the results of the MIBI studies. Conclusion Our results suggest the need to reassess the Workshop guidelines for the treatment of hyperparathyroidism in Japanese patients. It is desirable that MIBI scintigraphy be performed whenever possible, as this modality is anticipated to play an important role in determining whether or not surgery is appropriate.