Metabolic-mineral study in patients with renal calcium lithiasis, severe lithogenic activity and loss of bone mineral density.

Introduction: This study assessed the presence of osteoporosis/osteopenia in patients with severe lithogenic activity and compared their metabolisms with those in patients without lithiasis or with mild lithogenic activity.

Methods: From a sample of 182 patients, those with osteopenia/osteoporosis at the hip and lumbar spine were studied separately in a two-pronged study. 66 patients with bone mineral densities (BMDs) < -1 standard deviation (SD) on a T-score scale at the hip were divided into three groups: group A1 without lithiasis (n = 15); group A2 with lithiasis and mild lithogenic activity (n = 22); and group A3 with lithiasis and severe lithogenic activity (n = 29). Similarly, 86 patients with BMDs < -1 SD on a T-score scale at the lumbar spine were divided into three groups: group B1 without lithiasis (n = 15); group B2 with lithiasis and mild lithogenic activity (n = 29); and group B3 with lithiasis and severe lithogenic activity (n = 42).

Results: Patients from group A3 exhibited significantly higher levels of bone remodelling markers as compared to groups A1 and A2. Urinalysis also revealed higher excretion of calcium in 24-hour assessments in this group. Patients from group B3 differed from groups B1 and B2 mainly in bone remodelling markers and 24-hour urinary calcium excretion, which were significantly elevated in patients from group B3.

Conclusion: Patients with calcium lithiasis and severe lithogenic activity in addition to osteopenia/osteoporosis present with higher levels of hypercalciuria and negative osseous balance, which possibly perpetuate and favour lithiasic activity.