BACKGROUND Several recent studies reported bone mineral density (BMD) reduction in pediatric patients with idiopathic hypercalciuria (IH). This longitudinal study aimed to evaluate BMD evolution in IH patients through three bone densitometry studies conducted over 20 years on average. A second objective was to evaluate urine calcium and citrate excretion during this period. METHODS Case notes of 34 patients diagnosed with IH at age 7.9 ± 3, alongside results of two bone densitometry studies, performed at 10.5 ± 2.7 (BMD1) and 14.5 ± 2.7 (BMD2) years of age, were reviewed. Patients underwent a third densitometry study in adulthood (BMD3) aged 28.3 ± 2.9. Mean follow-up duration (time-lapse between BMD1 and BMD3) was 17.7 ± 1.4 years. RESULTS Statistically significant differences were found between z-BMD3 (- 0.85 ± 1.10) and z-BMD1 (- 1.47 ± 0.99) (P = 0.001) as well as between z-BMD3 and z-BMD2 (- 1.33 ± 1.20) (P = 0.016). At the end of follow-up, z-BMD3 was superior to z-BMD2 in 23 adult patients (67.6%) and lower in 11 patients (5M, 6F; 32.3%). Both men and women showed increased bone mass over time, although such increases were significant only for women. The gradual decrease observed in calcium/creatinine and citrate/creatinine ratios could be related to improvement in osteoblastic activity and especially reduction in osteoclastic activity. CONCLUSIONS In patients with IH, BMD improves, which may be related especially to female sex, increment of body mass, and reduction in bone resorption. Upon reaching adulthood, urine calcium and citrate excretion tend to decrease so lithogenic risk still remains. The cause of the latter is unknown, although it likely relates to changes in bone activity.

中文翻译：

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特发性高钙尿症患者骨矿物质密度的演变：一项为期 20 年的纵向研究。

背景 最近的几项研究报告了患有特发性高钙尿症 (IH) 的儿科患者的骨矿物质密度 (BMD) 降低。这项纵向研究旨在通过平均超过 20 年的三项骨密度测定研究来评估 IH 患者的 BMD 演变。第二个目标是评估在此期间尿钙和柠檬酸盐的排泄量。方法 回顾了 34 名在 7.9 ± 3 岁时被诊断为 IH 的患者的病例记录，以及在 10.5 ± 2.7 (BMD1) 和 14.5 ± 2.7 (BMD2) 岁时进行的两项骨密度测定研究的结果。患者在成年期 (BMD3) 接受了第三次密度测定研究，年龄为 28.3 ± 2.9。平均随访时间（BMD1 和 BMD3 之间的时间间隔）为 17.7 ± 1.4 年。结果发现 z-BMD3 (- 0.85 ± 1.10) 和 z-BMD1 (- 1.47 ± 0. 99) (P = 0.001) 以及 z-BMD3 和 z-BMD2 (- 1.33 ± 1.20) (P = 0.016) 之间。在随访结束时，23 名成年患者 (67.6%) 的 z-BMD3 优于 z-BMD2，11 名患者 (5M, 6F；32.3%) 低于 z-BMD2。随着时间的推移，男性和女性都表现出骨量增加，尽管这种增加只对女性显着。在钙/肌酐和柠檬酸盐/肌酐比率中观察到的逐渐降低可能与成骨细胞活性的改善，尤其是破骨细胞活性的降低有关。结论 IH 患者 BMD 改善，这可能与女性、体重增加和骨吸收减少特别相关。成年后，尿钙和柠檬酸盐的排泄量趋于减少，因此结石风险仍然存在。后者原因不明，