Relationship between the weight of parathyroid glands and their secretion of parathyroid hormone in hemodialysis patients with secondary hyperparathyroidism.

Secondary hyperparathyroidism is one of the common and important abnormalities of mineral metabolism in hemodialysis patients. In this study we investigated the relationship between the weight of individual parathyroid glands (PTG) and their secretion of parathyroid hormone (PTH). Sixty-four PTGs in 16 patients undergoing parathyroidectomy (PTx) at our hospital were included in this study. Patients' ages ranged from 34 to 68 years (60.3 +/- 6.6 years). They were undergoing maintenance dialysis therapy for 81-256 months (175.3 +/- 56.0 months). The cause of end-stage renal failure was chronic glomerulonephritis in all patients. We measured whole PTH (wPTH) levels before PTx and 15 min after the resection of each individual gland (Delta whole PTH). A positive correlation was found between the weight of individual gland and ultrasonography (US) size of individual PTG (r = 0.91, P < 0.001, N = 53). A positive correlation was found between the total mass of the gland and the total volume of PTG on US (r = 0.896, P < 0.001, N = 16). A positive correlation was found between the mass of each individual gland and Delta whole PTH (r = 0.625, P < 0.001, N = 64); however, massive PTGs did not secrete more whole PTH per unit mass (0.01 g). Determination of the volume of PTGs by US is a good indicator of their weight. Larger PTGs secrete more whole PTH per gland, whereas these PTGs did not have the ability to secrete more PTH per unit volume.