CONTEXT The latest guidelines of the 4th International Workshop on Asymptomatic Primary Hyperparathyroidism (aPHPT) reintroduced hypercalciuria (i.e. urinary calcium > 400 mg/day) as criterion for surgery. However, the value of hypercalciuria as a predictor of nephrolithiasis and the correct cut-off values still need to be confirmed. OBJECTIVE To evaluate the prevalence of silent kidney stones in a large series of patients with aPHPT and the sensibility, specificity and predictive value of different cut-off values of hypercalciuria in identifying patients with nephrolithiasis. DESIGN One hundred seventy-six consecutive patients with aPHPT were evaluated at our Institution by serum and urinary parameters and kidney ultrasound. RESULTS Silent nephrolithiasis was found in 38 (21.6%) patients. In the univariate and multivariate model, hypercalciuria was a predictor of nephrolithiasis using the criterion of 400 mg/24 h [(OR 2.30, (1.11-4.82) P = 0.025], 4 mg/kg/bw [OR 2.65, (1.14-6.25) P = 0.023], gender criterion [OR 2.79, (1.15-6.79) P = 0.023] and the cut-off value derived from the ROC analysis [(> 231 mg/24 h) OR 5.02 (1.68-14.97) P = 0.004]. Despite these several predictive criteria, however, hypercalciuria had a low positive predictive value (PPV), ranging from 27.4 to 32.7%. CONCLUSIONS Hypercalciuria is a predictor of nephrolithiasis, but its PPV is low.

中文翻译：

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高钙尿症：作为无症状原发性甲状旁腺功能亢进症肾结石的预测危险因素的价值？

背景第四届无症状原发性甲状旁腺功能亢进症国际研讨会（aPHPT）的最新指南重新引入了高钙尿症（即尿钙> 400 mg /天）作为手术标准。但是，高钙尿症作为肾结石病的预测指标的值和正确的临界值仍然需要确认。目的评估大量aPHPT患者无声肾结石的患病率，以及高钙尿症的不同临界值在鉴别肾结石病中的敏感性，特异性和预测价值。设计在我们的机构中​​通过血清和尿液参数以及肾脏超声评估了176例连续的aPHPT患者。结果在38名（21.6％）患者中发现了沉默的肾结石病。在单变量和多变量模型中，尽管有这些预测标准，但高钙尿症的阳性预测值（PPV）较低，介于27.4％至32.7％之间。结论高钙尿症是肾结石症的预测指标，但其PPV较低。尽管有这些预测标准，但高钙尿症的阳性预测值（PPV）较低，介于27.4％至32.7％之间。结论高钙尿症是肾结石症的预测指标，但其PPV较低。