PARtICulARItIes of Bone MetABolIsM And CAlCIuM RegulAtoRs In A gRouP of young MAles wIth IdIoPAthIC hyPeRCAlCIuRIA And RelAPsIng KIdney lIthIAsIs

220 Acta Endocrinologica (Buc), vol. X, no. 2, p. 220-227, 2014 *Correspondence to: Lacramioara Serban MD, “Gr.T.Popa” University of Medicine and Pharmacy Iasi Physiology, Universitatii Str. 16, Iasi, 700115, Romania, E-mail: [email protected] Abstract Background. Idiopathic hypercalciuria is a risk factor for nephrolithiasis. Both renal stones and hypercalciuria are associated with lower bone mineral density (BMD), but the relationship between these modifications is not completely understood. Aims. To evaluate some metabolic particularities possibly related to relapsing nephrolithiasis (RN) in young male patients. Methods. We performed a crosssectional study including a group of 30 young male patients with RN and a group of 30 healthy, age and BMI (body mass index) matched controls (CTR). We evaluated calcium and phosphate metabolism, bone remodeling markers alkaline phosphatase (AP) and osteocalcin in serum and 24-hour urine samples, and lumbar and hip BMD. Results. We observed higher values of serum calcium (P<0.05) and 24 hour urinary calcium (P<0.001) in the RN group. Parathyroid hormone (PTH) and AP were also higher in the RN group (P<0.01), whereas serum 25OH-D 3 was lower (P<0.01). BMD, T and Z scores were lower in the RN group in both the lumbar (P<0.01) and hip (P<0.05) regions. Conclusions. Young male patients with hypercalciuric RN have lower BMD and higher bone turnover. Higher PTH levels related to vitamin D deficiency may contribute to bone demineralization in certain cases.