Pulmonary function tests in patients with primary hyperparathyroidism

CONTEXT: There is limited information on respiratory muscle functions in patients with primary hyperparathyroidism (PHPT). AIM: To assess respiratory muscle dysfunction in patients with PHPT. SETTING AND DESIGN: This prospective study was carried between January 2005 and December 2006 by the Department of Endocrinology at the Postgraduate Institute of Medical Education and Research, Chandigarh. MATERIALS AND METHODS: PHPT was defined as elevated parathyroid hormone in the presence of hypercalcemia. Spirometry was performed using a dry rolling seal spirometer and spirometric indices like forced vital capacity (FVC), forced expiratory volume in first second (FEV(1)), and FEV(1)/FVC ratio were measured using standard guidelines. RESULTS: Thirty patients were studied with a mean age of 37.1 ± 2.4 years and 18 were women. The most common presenting symptoms were fatigue (75.0%) and bone pain (60.70%). The mean (±SD) of percentage predicted FVE(1), FVC, FEV(1)/FVC ratio, PEF, and FEF were 98.7 ± 16.1, 93.9 ± 14.7, 84.5 ± 3.4, 89.3 ± 22.5, and 99.7 ± 33.6, respectively. Two had obstructive lung disease and two had restrictive lung disease. We did not find correlation with preoperative serum calcium, phosphate, and PTH with FVE(1), FVC, FEV(1)/FVC ratio, PEF, and FEF. CONCLUSION: Elevated calcium, low phosphate, and elevated PTH levels in patients with moderate to severe PHPT do not significantly affect respiratory muscle functions.