Elevated bone aluminum and suppressed parathyroid hormone levels in hypercalcemic dialysis patients.
We studied 21 dialysis patients who became hypercalcemic without vitamin D or calcium therapy and compared them to 28 dialysis patients who were not hypercalcemic. In the hypercalcemic group, the mean ionized-calcium level was elevated compared to normal subjects (5.4 +/- 0.4 vs. 4.9 +/- 0.1; p less than 0.001), while the ionized-calcium level in the control dialysis patients was below normal (4.5 +/- 0.4 vs. 4.9 +/- 0.1; p less than 0.001). Bone biopsies were performed in all patients. Two thirds of the hypercalcemic patients had low-turnover osteodystrophy (LTO, predominantly osteomalacia), a fraction significantly higher than in the control dialysis patients (13/21 vs. 8/28, respectively; p less than 0.05). The hypercalcemic patients with LTO had markedly elevated surface bone aluminum (63 +/- 24% of all trabecular surfaces). In contrast, the nonhypercalcemic dialysis patients with LTO and all patients with osteitis fibrosa had minimal surface bone aluminum. Hypercalcemic patients with osteitis fibrosa had a significantly lower mean N-terminal parathyroid hormone (PTH) value than did nonhypercalcemic patients with osteitis fibrosa (149 +/- 81 vs. 278 +/- 135 pg/ml, respectively; p less than 0.005). Both mean values were markedly elevated in comparison with those obtained in normal subjects (16 +/- 5 pg/ml). In contrast, patients with LTO, irrespective of the calcium level, had mean PTH values that were not significantly different from those of normal subjects. A PTH level greater than 100 pg/ml was 95% sensitive and 87% specific for osteitis fibrosa, as demonstrated by histomorphometry in nonhypercalcemic dialysis patients. However, this level was only 62% sensitive and 77% specific for a diagnosis of osteitis fibrosa in hypercalcemic dialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Medicine, University of Pittsburgh, Pa.
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B
Piraino
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Chen
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JB
Puschett
D000328:Adult; D000368:Aged; D000535:Aluminum / Q000378:metabolism*; D001842:Bone and Bones / Q000378:metabolism* / Q000473:pathology; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000150:complications* / Q000473:pathology; D005260:Female; D005357:Fibrous Dysplasia of Bone / Q000150:complications; D005500:Follow-Up Studies; D006801:Humans; D006934:Hypercalcemia / Q000209:etiology / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D006435:Renal Dialysis
D010281:Parathyroid Hormone; D000535:Aluminum