Correlation Between Serum Parathormone Levels With Urinary Magnesium Excretion in Patients With Non-Dialytic Chronic Kidney Disease

Abstract

Background: Disorders of mineral metabolism occur in most patients with chronic kidney disease (CKD). The aim of this work was to correlate serum parathyroid hormone (PTH) levels with urinary magnesium excretion in patients with non-dialysis CKD. Methods: Cross-sectional study with patients with CKD undergoing non-dialysis treatment in stages 3A, 3B and 4. Concentrations of creatinine, magnesium, calcium, phosphorus, parathyroid hormone, vitamin D and alkaline phosphatase were determined in blood samples. The assessment of urinary magnesium levels was performed by means of total daily excretion and by the excretion fraction (FEMg). Results: The study evaluated 163 patients with mean age of 60.7 ± 11.7 and 51.0% were male. A positive correlation was observed between PTH and alkaline phosphatase (r = 0.26; p = 0.006) and FEMg (r = 0.17; p = 0.020). Calcium (r = -0.23; p = 0.002), magnesium in 24-hour urine (r = -0.18; p = 0.020) and estimated glomerular filtration rate (r = -0.47; p = 0.001) demonstrated negative correlation with PTH. Conclusion: Elevated levels of PTH correlated positively with FEMg, regardless of the presence of serum magnesium alterations, and FEMg can be used as another indicator for the treatment of hyperparathyroidism.