Endocrine Abstracts

Introduction: A relationship between osteopenia/osteoporosis and calcium nephrolithiasis has been recognized in several studies. An association has also been observed between bone mineral density loss, hypercalciuria, hypocitraturia and nephrolithiasis.

The aim of this study was to analyze the effects of aminobisphosphonates and thiazides on renal lithogenic activity and bone mineral density in patients with recurring renal calcium lithiasis.

Methods/design: A prospective cohort study with a 3-year clinical follow-up was performed in two groups of patients with recurring calcium lithiasis, hypercalciuria and bone mineral density loss. Group 1 included 35 patients undergoing treatment with 70 mg/week alendronate, and Group 2 included 35 patients undergoing treatment with 50 mg/day alendronate and 70 mg/week hydrochlorothiazide. Biochemical analysis was performed at baseline, 6 months and 2 years, bone densitometry at baseline and at 2 years and clinical follow-up during 3 years of treatment. Biochemical variables in blood and urine, recurrent lithiasis and bone mineral density were analyzed.

Results: Age, sex, baseline biochemical markers and bone density showed no differences between treatment groups at the onset of treatment. After 2 years of treatment, Group 1 showed a significant decrease in bone turnover markers and calciuria as well as a significant improvement in bone mineral density. After 2 years of treatment, Group 2 showed a decrease in calciuria and in bone markers. Bone densitometry improved significantly. At 2 years, the decrease in calciuria and the improvement in bone mineral density were greater in Group 2 in than Group 1, and the difference was statistically significant.

Conclusion: Aminobisphosphonates improve bone mineral density and slow lithogenic activity; however, administration of aminobisphosphonates in association with thiazides produces the same clinical effects and also reduces calciuria and improves bone mineral density. Bisphosphonate-thiazide coadministration is most appropriate in patients with bone mineral density loss, hypercalciuria and relapsing calcium lithiasis.

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.