Abstract: FR-PO399

Magnesium and Progression of CKD in Children Enrolled in the CKiD Study

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 301 CKD: Risk Factors for Incidence and Progression

Authors

  • Turman, Martin A., Phoenix Children's Hospital, Phoenix, Arizona, United States
  • Betoko, Aisha, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States
  • Schwartz, George J., University of Rochester, Rochester, New York, United States
  • Furth, Susan L., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States
  • Warady, Bradley A., The Children's Mercy Hospital, Kansas City, Missouri, United States

Group or Team Name

  • CKD in Children Study
Background

Studies in adults with CKD demonstrate that lower magnesium (Mg) levels correlate with more rapid progression of CKD. We hypothesized that hypomagnesemia is associated with more rapid disease progression in children with CKD.

Methods

We measured the initial serum Mg level in 418 children enrolled in the first cohort of the Chronic Kidney Disease in Children (CKiD) study. Participants were grouped into low Mg (< 1.7 mg/dL, n=84; 20%), intermediate Mg (1.7-1.9 mg/dL, n=217; 52%) or high Mg (2.0-2.7 mg/dL, n=117; 28%) categories. Using parametric failure-time models, we evaluated the association between Mg level and CKD progression, defined as time to the composite event of renal replacement therapy (dialysis or kidney transplant) or 50% decline in estimated glomerular filtration rate (eGFR) after adjustment for the following potential confounders: initial eGFR, proteinuria, age, sex, race, BMI, Tanner stage, anemia, hypertension, and CKD diagnosis.

Results

Median age was 11 years, 62% were male and 58% non-Hispanic white. Median eGFR and urine protein-to-creatinine (UP/C) ratio were 45.3 ml/min/1.73m2 and 0.4 mg:mg, respectively; 21% of the children had a glomerular diagnosis. The baseline characteristics of the patients in the three groups were not significantly different with regard to all potential confounders except initial eGFR and proteinuria. Participants in the low Mg group had a significantly higher baseline eGFR, and lower UP/C ratio compared to those in the high Mg category (median [IQR]: 51 [41, 63] vs. 37 [29, 50] and 0.3 [0.1, 1.0] vs. 0.6 [0.2, 1.7] respectively). Mg levels were not significantly different for participants on diuretics (n=28), calcineurin inhibitors (n=14), or Mg supplements (n=7). After adjustment for potential confounders, the relative times to either 50% decline in eGFR or renal replacement therapy were not significantly different among Mg groups.

Conclusion

Hypomagnesemia (Mg <1.7 mg/dL) is surprisingly prevalent (20%) in pediatric patients with CKD. This high rate of hypomagnesemia does not correlate with diuretic or calcineurin inhibitor use. Unlike studies in adult populations, hypomagnesemia does not correlate with more rapid progression of pediatric CKD. Higher Mg levels (Mg>2.0 mg/dL) do not correlate with more rapid progression of pediatric CKD either.

Funding

  • NIDDK Support