[Estimation of selected markers of bone metabolism inpatients with nephrolithiasis]

19 patients with active nephrolithiasis, 14 patients with non-active nephrolithiasis and 17 healthy subjects were examined. After 7 days consumption of standardized low calcium, low phosphate, low purine and low protein diet, plasma parathyroid hormone (PTH) and osteocalcin concentration, activity of the alkaline phosphatase and its bone fraction were assessed before and after 4 hours i.v. infusion of calcium gluconate (15 mg/kg b.w. in 500 ml 0.9% NaCl). In addition, urinary excretion of oxalate, calcium, phosphate and magnesium were estimated in all examined groups.

1. In comparison to healthy subjects, patients with nephrolithiasis are characterized by higher plasma PTH and osteocalcin concentration, increased activity of bone fraction of alkaline phosphatase and urinary oxalate and calcium excretion. 2. Disturbances of calcium-phosphate and oxalate metabolism, PTH secretion and bone osteoblastic activity found in patients with active nephrolithiasis are qualitatively similar but quantitatively more intensive than in patients with non-active nephrolithiasis.