Endocrine Abstracts

Introduction: Calcium nephrolithiasis is the most frequently diagnosed type of nephrolithiasis. It is related to metabolic alterations, inhibitor deficiencies, anatomical factors, alterations in urinary pH, and bone alterations.

The objective of this study is to analyze the alterations in bone mineral density and bone and calcium-phosphorus metabolism in patients with calcium nephrolithiasis.

Methods/design: We designed a study with 182 patients who were distributed among three groups: Group O included 56 patients without nephrolithiasis; group A included 67 patients with calcium nephrolithiasis and mild lithogenic activity; and group B included 59 patients with calcium nephrolithiasis and severe lithogenic activity. Metabolic parameters of blood and urine that were related to calcium-phosphorous and bone metabolism and bone densitometry were assessed in all patients. A comparative study was performed on the variables of bone and calcium-phosphorus metabolism and bone densitometry as well as the presence or absence of osteopenia/osteoporosis among the groups.

Results: The patients in group B had a greater loss of bone mineral density, measured by the T-score, than the patients in groups O and A. Moreover, the proportion of patients in group B with osteopenia/osteoporosis was statistically significantly higher than the proportion of patients in groups O and A. We observed higher values of calciuria, fasting calcium/creatinine ratio, and 24-h calcium/creatinine among the patients in group B compared to the other two groups. Calciuria, citraturia, and fasting calcium/creatinine were independent factors that showed a relationship with severe lithogenic activity compared to the control group, and -crosslaps is an independent factor that has a relationship with severe lithogenic activity as compared to mild lithogenic activity.

Conclusions: Patients with calcium lithiasis and severe lithogenic activity have a greater loss in bone mineral density and therefore a greater risk of osteopenia/osteoporosis compared to patients without lithiasis or with calcium lithiasis and mild lithogenic activity.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.