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Objectives. Hypocitraturia is a risk factor for calcium nephrolithiasis. 1,25(OH) 2 D 3 influences renal citrate handling and enhances citraturia. The aim of this study was to evaluate the relationship between vitamin D receptor (VDR) allelic variant and urinary citrate excretion in recurrent stone formers (SF) patients. Design. Case-control study. Subjects. A total of 220 recurrent calcium oxalate SF patients and 114 healthy control (C) subjects were enrolled for this study. Subjects with urinary tract infections, hyperparathyroidism, cystinuria >70 lmol/24 h, gouty diathesis, renal tubular acidosis, renal failure, chronic diarrhoeal states, intake of thiazide diuretics, angiotensin-converting enzyme (ACE)-inhibitors, glucocorticoids or oestrogens were excluded. A standard constant diet was given for 7 days. The 24-h urinary citrate excretion and the active tubular reabsorption of filtered citrate (Rcit) were evaluated. Hypocitraturia was defined as a urinary citrate excretion lower than 1.7 mmol day )1 .Stone formers patients and C were genotyped for BsmI and TaqI VDR alleles. Contingency table chi-square tests were used to compare genotype frequencies in hypocitraturic SF patients, normocitraturic SF and C.Results. The prevalence of hypocitraturia in SF patients was 32.7% (72 of 200). Hypocitraturia in these patients resulted from excessive Rcit of a normal load of citrate. We found a different distribution (P < 0.05) of BsmI and TaqI VDR genotypes in hypocitraturic SF patients compared with normocitraturic SF and C. In particular, the prevalence of bb and TT VDR genotypes in hypocitraturic SF was significantly higher than in normocitraturic SF and C. Conclusions. These results point to a genetic association between BsmI and TaqI VDR polymorphisms and idiopathic hypocitraturia in calciumoxalate recurrent SF patients.

Recurrent calcium oxalate stone formers with IHc and the bT VDR haplotype have more aggressive kidney stone diseases as indicated by a higher familial incidence and lower mean age at onset. This clinical severity is associated with the higher urinary supersaturation of calcium oxalate salts and abnormalities of renal citrate handling.

Reduced midwall mechanics is associated with lower CFR, a relationship that depends on LV concentric geometry. A reduced CFR is associated with both impaired relaxation and increased filling pressure, a relation that is independent of LV geometry and pressure load.

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The aim of this study was to evaluate the efficacy and safety of risedronate and pamidronate in 30 patients (mean age = 57.86 +/- 8.90 years) with severe Paget's disease of bone (PDB), showing acquired resistance to intravenous (IV) clodronate treatment. Fifteen patients were treated with oral risedronate (30 mg/day for 8 weeks). Treatment was repeated in patients without evidence of PDB remission [total alkaline phosphatase (tALP) serum levels in the normal range] at day 120. Fifteen patients were treated with IV pamidronate (30 mg/day for 3 days). Pamidronate treatment (60 mg/day for 3 days) was repeated in patients without evidence of PDB remission at day 120. At day 60, a significant decrease in tALP serum levels was obtained in all pagetic patients. At day 360, 13 (86.6%) patients treated with risedronate achieved PDB remission, 9 patients during the initial treatment and 4 after retreatment. Two patients showed a significant decrease in tALP serum levels without clinical remission after two risedronate treatments. At the same time, 12 (80%) patients treated with pamidronate achieved PDB remission, 6 patients during the first treatment and 6 after retreatment. Three patients showed a significant decrease in tALP serum levels but no clinical remission after two pamidronate courses. Two of these patients showed a relapse during the study. The incidence of minor side effects and transient hyperparathyroidism related to bisphosphonate treatment was significantly lower after risedronate therapy. In patients with resistant PDB, oral risedronate therapy has comparable efficacy to IV pamidronate with a lower incidence of treatment-related side effects.

Primary pachydermoperiostosis (PDP) is a rare syndrome, characterized by digital clubbing, periostosis, and pachydermia. We have evaluated biochemical bone turnover markers, including components of interleukin-6 (IL-6) and osteoprotegerin/receptor activator of nuclear factor (NF)-kappaB ligand (OPG/RANKL) systems, in an 18-year-old man affected by primary PDP. The acute phase of the disease was characterized in our patient by high serum levels of IL-6 and RANKL. The observed high serum levels of these parameters are associated with increased values in markers of bone resorption (degradation products of C-terminal telopeptides of type-I collagen and urinary hydroxyproline/creatinine ratio) and reduced serum levels of bone alkaline phosphatase, a marker of bone formation. Serum levels of osteotrophic hormones were in the normal range. Our data suggest that, despite the radiographic findings, the acute phase of primary PDP is characterized by increased bone resorption, probably mediated by IL-6 and RANKL.