Rendina D, De Filippo G, Merlotti D, et al. - This cross-sectional multicentric study was undertaken to compare Paget Disease of Bone (PDB) patients (n = 708) with controls (n = 1,803) in terms of prevalence of primary hyperparathyroidism (HPTH) and nephrolithiasis (NL). Researchers also assessed the prevalence of NL-metabolic risk factors among 97 PDB patients with NL, 219 PDB patients without NL, 364 NL patients without PDB and 219 controls, all of them without HPTH. Higher prevalence of primary HPTH and NL was identified in PDB patients vs controls. A higher prevalence of hyperoxaluria was observed in PDB patients with NL vs NL patients without PDB and in PDB patients without NL vs controls. Overall, findings demonstrated NL and HPTH as frequent metabolic complication of PDB. Experts advised assessing NL occurrence in PDB cases, especially in those with polyostotic disease and/or after aminobisphosphonate therapy, to employ an adequate prevention strategy.