Decreased in vitro osteoblast proliferation and low turnover bone disease in nonuremic proteinuric patients

Patients with proteinuria, even those with normal glomerular filtration rate, often present abnormal bone histology. We evaluated bone histology and the in vitro proliferation of osteoblasts in samples obtained from 17 proteinuric patients with primary glomerulopathies. Histomorphometric analysis of bone biopsies was performed, and bone fragments were obtained for osteoblast culture, in which we evaluated cell proliferation. In comparison to controls, patients presented lower trabecular bone volume (20.9±14.5% vs 26.8±5.9%; P=0.0008); lower trabecular number (1.7±0.2/mm vs 2.0±0.3/mm; P=0.004); and greater trabecular separation (475.5±96.4μm vs 368.3±86.2μm, P=0.0002). We also found alterations in bone formation and resorption: lower osteoid volume (0.9±0.7% vs 2.0±1.4%; P=0.0022); lower osteoid thickness (6.4±2.8μm vs 11.5±3.2μm; P