Association of Severe Calcium Lithogenic Activity and Bone Remodeling Markers

OBJECTIVE To establish cutoff points for markers of bone remodeling that allow for screening of patients at risk for serious lithogenic activity. MATERIALS AND METHODS We conducted a cross-sectional study with 182 patients (aged between 25 and 60 years) divided into 3 groups: group 1, 56 patients without lithiasis; group 2, 67 patients with light calcium lithiasis; and group 3, 59 patients with severe calcium lithiasis. The criteria for inclusion in and exclusion from the study were established, and light and severe lithogenic activity were defined. Metabolic variables in blood and urine, along with bone densitometry, were studied for the groups. Statistical analysis of the results and preparation of receiver operating characteristic curves to establish optimal cutoff points were performed. RESULTS The patients in group 3 showed the greatest bone mineral density loss and the highest values for markers of bone remodeling, together with increased 24-hour calciuria. Using the receiver operating characteristic curves developed and based on statistical significance (P = .0001), the following cutoff points for severe lithogenic activity, with a sensitivity between 75% and 85%, were established: beta-crosslaps >0.331 ng/mL; osteocalcin >13.2 ng/mL; beta-crosslaps/osteocalcin >0.024; 24-hour calciuria >306.6 mg; and fasting urine calcium/creatinine >0.105. CONCLUSION Patients with calcium lithiasis and elevated values for osteocalcin, beta-crosslaps, beta-crosslaps/osteocalcin, 24-hour calciuria, and fasting urine calcium/creatinine may present a high risk of severe lithogenic activity. (C) 2013 Elsevier Inc.