Evaluation of bone microarchitecture and finite element and their association with anthropometric, densitometric biochemical and hormonal parameters in hypercalciuric nephrolithiasis patients

• Grant number: 16/25359-0
• Support type: Regular Research Grants
• Duration: October 01, 2017 - March 31, 2020
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Ita Pfeferman Heilberg
• Grantee: Ita Pfeferman Heilberg
• Home Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Assoc. researchers: Rosa Maria Rodrigues Pereira

Abstract

Idiopathic Hypercalciuria (IH) is the most common metabolic abnormality among lithiasics patients, accounting for up to 40% of cases of nephrolithiasis. An inverse association between calcium excretion and Bone Mineral Density (BMD) has been demonstrated in both stone formers and non-stone formers. Several studies have found decreased trabecular and cortical BMD among IH patients. Bone Densitometry is considered the gold standard method for detecting high-risk patients for osteoporosis, and can predict the fracture risk quite well in the general population. However, given that bone densitometry misses information assessed by a three dimension analysis, it cannot provide insights into bone microarchitecture, hence being an inaccurate method to predict fracture in some populations. Histomorphometric analysis through bone biopsy is the gold standard for evaluation of bone volume, turnover and mineralization. Previous histomorphometric studies by our group have demonstrated that hypercalciuric nephrolithiasis patients have increased bone reabsorption, low bone formation and mineralizaton defects and immunohistochemical analysis disclosed that RANKL has a major role in bone reabsorption in these patients.(Process FAPESP 2003/09271-5) Another study by our group has evidenced that the vitamin D receptor (VDR), sclerostin and 1,25 dihydroxyvitamin D also possesses a role in increasing bone reabsorption in IH patients (Process FAPESP 2008/515-0). New non-invasive technologies have been created to evaluate bone microarchitecture as an alternative method to bone biopsy, including the High Resolution Peripheric Quantitative Tomography (HR-pQCT). The information provided by such an exam can also be analyzed by the Finite Element (FE), a software that simulates mechanical tests in order to calculate bone mechanical properties and loading conditions. The study of bone microarchitecture along with biochemistries and hormonal bone markers from hypercalciuric nephrolithiasis patients can contribute to better understand the underlying mechanisms for bone loss and help to develop future strategies of treatment that may improve bone quality in this population. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MELO, THALITA LIMA; GONCALVES ESPER, PRISCILA LIGEIRO; ZAMBRANO, LYSIEN IVANIA; ORMANJI, MILENE SUBTIL; RODRIGUES, FERNANDA GUEDES; HEILBERG, ITA PFEFERMAN. Expression of vitamin D receptor, CYP27B1 and CYP24A1 hydroxylases and 1,25-dihydroxyvitamin D-3 levels in stone formers. UROLITHIASIS, NOV 2019. Web of Science Citations: 0.