Effects of Magnesium Supplementation on the Carotid Intima Media Thickness in Children with Chronic Kidney Disease and Hyperphosphatemia: A Double-blind Randomized Clinical Trial

Background: Hyperphosphatemia has been emphasized to be a significant risk factor for vascular calcification in CKD patients. This study aims to investigate the effect of magnesium supplementation on the reduction of phosphate levels and carotid intima media thickness in children as predictor on vascular calcification with CKD and hyperphosphatemia, compared to a placebo. Methods: A randomized, double-blind, placebo-controlled trial was conducted at Pediatric Ward and Outpatient Clinic of Pediatric Nephrology in our setting during October-March 2023. We compared oral magnesium supplementation (6 mg/kg body weight/day for two months) with a placebo in children with CKD and hyperphosphatemia (ages 1-18 years old). Patients who were on dialysis and had serum magnesium levels of <1.6 mg/dL and >2.4 mg/dL, and were allergic to magnesium supplementation were excluded. A paired T-test and the Wilcoxon signed-rank test were used for statistical analysis. Results: We collected 25 children in the experimental group and 25 children in the placebo group. Phosphate levels were decreased in both the magnesium supplementation and placebo groups (6.1 ± 0.79 to 6.0 ± 0.63 mg/dL; p-value = 0.852 and 6.01 ± 0.55 to 5.8 ± 0.64 mg/dL; p-value=0.365). However, when compared between groups, the reductions were not significantly different (0.1 vs 0.21; p-value=0.935). A significant improvement was found in carotid intima media thickness in both groups (0.05±0.01 to 0.05±0.01; p-value=0.000 and 0.05±0.01 to 0.05±0.01; p-value=0.000), and the reductions were significantly different (0.01 vs 0.01; p-value=0.000). Conclusion: Magnesium supplements have considerably lower phosphate levels and significantly reduced the thickness on carotid intima media in children with CKD and hyperphosphatemia.