Unique clinical characteristics of primary hyperparathyroidism in India

Background: The features of primary hyperparathyroidism (PHPT) in developin g countries have rarely been examined. This study explored the clinical cha racteristics of PHPT in India with the hypothesis that this may improve und erstanding of the pathogenesis of the disease worldwide. Methods: Consecutive patients with PHPT (24 women, five men) were examined prospectively before and after parathyroidectomy. Results: All patients had osteitis fibrosa cystica with a median symptom du ration of 2.5 (range 1-26) years. Single or multiple fragility fractures we re present in 14 patients (eight were bedridden); 20 had brown rumours. A l ean preoperative serum calcium was 3.1 mmol/I, while mean serum intact para thyroid hormone (iPTH) and total alkaline phosphatase (ALP) levels were 17- fold and 12-fold higher than normal respectively. Nine patients had overt r enal damage, mainly nephrocalcinosis, Parathyroidectomy invariably resulted in severe hypocalcaemia, necessitating long-term vitamin D treatment, The mean parathyroid gland weight was 8.6 (range 2.0-36.6) g and features of ca rcinoma were found in four patients. Serum calcidiol level correlated inver sely (P < 0.05) with serum iPTH and ALP, and parathyroid gland weight. Conclusion: PHPT in Indians is a severe, symptomatic disorder with skeletal , muscular and renal manifestations at a young age. The presence of this se vere variant of PHPT in vitamin D-sufficient Indians, and the lack of skele tal disease in other vitamin D-deficient populations, raises the possibilit y of additional pathogenetic factors.