The clinical significance of calcium/magnesium ratio in primary hyperparathyroidism: unveiling a clinical association

PURPOSE

In previous studies, magnesium (Mg) was found to be lower in cases with more severe primary hyperparathyroidism (PHPT) and higher calcium (Ca) levels. This study evaluated the relationship between serum Mg and serum Ca and phosphorus (P) levels in PHPT and their utility in determining the presence of osteoporosis and nephrolithiasis.

METHODS

Patients who were followed up with PHPT between March 2019 and March 2023 were analyzed retrospectively. Biochemical data, renal ultrasonography results, dual-energy x-ray absorptiometry (DEXA) reports, and technetium 99 m sestamibi parathyroid scintigraphy reports were obtained. MgxP, Mg/P, Ca/P, and corrected Ca (cCa)/P values were calculated. The relationships between biochemical parameters and clinical outcomes were evaluated statistically.

RESULTS

A total of 543 patients were included in the study. Patients with nephrolithiasis had higher cCa/Mg or Ca/Mg than those without nephrolithiasis. Additionally, ROC analysis revealed that cCa/Mg greater than 5.24 could identify the presence of nephrolithiasis with a sensitivity of 73.3% and a specificity of 73%. No statistically significant correlation existed between the results of the Mg/P, MgxP, cCa/Mg, Ca/Mg values, and DEXA-bone mineral densitometry(BMD).

CONCLUSION

Ca/Mg and cCa/Mg ratios in particular seem more valuable in determining the presence of nephrolithiasis than the currently used 24-h urine Ca measurement. Compared to urinary Ca measurements, they are cheaper, more practical, and more accessible.

What Is the Role of Sensorineural Hearing Loss in Fabry Disease Screening?

Objective

Fabry disease is a rare hereditary lysosomal storage disease caused by the deficiency of alpha-galactosidase A (α-GLA). Although sensorineural hearing loss is common in Fabry disease, there are no studies in the literature that have screened a population with sensorineural hearing loss for Fabry disease. In this study, we aimed to screen a group of patients who were diagnosed with sensorineural hearing loss and underwent a hearing test for Fabry disease.

Methods

One hundred sixty eight patients who were aged 18-75 years and diagnosed with idiopathic hearing loss between July 2019 and January 2020 were included. In male patients, α-GLA enzyme activity was analyzed. Patients with low enzyme activity were identified and genetic testing was performed for mutations in the GLA gene. In females, only genetic testing was performed.

Results

Eighty four women and 84 men were included in the study. α-GLA enzyme activity was low in 11 of the 84 male patients (13%). One out of these 11 patients had a gene mutation for Fabry disease. Moreover, four relatives of this index patient were diagnosed with Fabry disease in family screening. GLA gene mutation was also found in one of the 84 female patients. Consequently, two (1.2%) of our 168 patients were diagnosed with Fabry disease by screening with enzyme activity and genetic testing.

Conclusion

Our study showed that screening for Fabry disease in patients with idiopathic sensorineural hearing loss without other specific findings might be a useful strategy for detecting new cases.