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The following is a summary of “Calcium to magnesium ratio as a superior biomarker for nephrolithiasis detection in primary hyperparathyroidism,” published in the January 2025 issue of Scientific Reports by Yalçın et al. 

Primary hyperparathyroidism (pHPT) causes mineral imbalances, leading to nephrolithiasis and osteoporosis, with growing interest in biochemical markers for improved diagnostic accuracy. 

Researchers conducted a retrospective study to evaluate the calcium-to-magnesium (Ca/Mg) ratio as a biomarker for nephrolithiasis, comparing it to 24-h urinary calcium excretion and exploring its clinical implications. 

They analyzed clinical, biochemical, and bone mineral density (BMD) data from 367 patients with pHPT. Nephrolithiasis was diagnosed via imaging, and the diagnostic performance of the Ca/Mg ratio and urinary calcium excretion was assessed through receiver operating characteristic analysis. Multivariable regression identified predictors of kidney stones. 

The results showed that the Ca/Mg ratio, with a cutoff of 6.35, had superior specificity (78%) compared to 24-hour urinary calcium excretion (44%) and comparable sensitivity (71% vs 78%). Elevated Ca/Mg ratios are strongly correlated with nephrolithiasis. Hypomagnesemia was linked to higher kidney stone prevalence, reduced BMD, and increased serum calcium and creatinine levels. 

Investigators found the Ca/Mg ratio to be a promising, non-invasive biomarker for nephrolithiasis in pHPT, outperforming traditional urinary calcium measures. The findings highlighted the need for further research into magnesium-targeted interventions for managing pHPT-related complications. 

Source: nature.com/articles/s41598-025-86954-4