Saponaro F, Marcocci C, Apicella M, et al. - Researchers investigated patients (n = 157) with asymptomatic sporadic primary hyperparathyroidism (PHPT), to examine the link of urinary stone risk factors and nephrolithiasis in these patients as well as its clinical relevance. Among participants, serum and 24-hour urinary parameters were measured and kidney ultrasound was performed. They examined urinary parameters in the univariate analysis as continuous and categorical variables. In univariate and multivariate analysis adjusted for age, gender, BMI, estimated glomerular filtration rate, parathyroid hormone, 25-hydroxyvitamin D, serum calcium, and urine volume, a significant link of only hypercalciuria and hypomagnesuria with nephrolithiasis was evident. Overall, in asymptomatic PHPT patients, hypomagnesuria and urinary calcium/magnesium ratio are each shown to be related to silent nephrolithiasis and were found to possess potential clinical utility as risk factors, besides hypercalciuria, for kidney stones. The findings did not lend support to other urinary indices that have been often considered to be related to kidney stones in PHPT.