FRAÇÃO DE EXCREÇÃO DE MAGNÉSIO (FEMg) E ASSOCIAÇÃO COM MARCADORES DE FUNÇÃO RENAL EM PACIENTES COM DOENÇA RENAL CRÔNICA NÃO DIALÍTICA

• DOI: https://doi.org/10.22533/at.ed.9832516099

• Palavras-chave: Doença renal crônica; Fração de Excreção de Magnésio (FEMg); marcador de função renal

• Keywords: Chronic kidney disease; Magnesium Excretion Fraction (FEMg); Renal Function marker

• Abstract: Background: Magnesium plays an important role in numerous physiological functions of the body, cell signaling, energy production, metabolism, cell growth and proliferation, synthesis of biomacromolecules, among others. It is currently known that the fraction of magnesium excretion (FEMg) can be an important parameter to monitor renal function and can be used as a predictor of progression of chronic kidney disease. This study evaluated the association between FEMg and laboratory markers of renal function in patients with non-dialytic chronic kidney disease and identified a cut-off point for the diagnosis of renal dysfunction. Methods: This is an analytical study, carried out in 128 patients with non-dialytic CKD (chronic kidney disease) (stages 3A, 3B and 4) undergoing treatment at the Kidney Disease Prevention Center (CPDR) of the University Hospital of the University Federal Maranhão (HU-UFMA) and 110 controls (GFR>60 ml/min/1.73 m²). Sociodemographic, clinical and laboratory data were collected (serum cystatin C, serum and urinary creatinine, serum and urinary albumin, serum and urinary magnesium, and albumin/creatinine ratio). Urinary magnesium levels were evaluated through total daily excretion and fraction of excretion (FEMg) and Glomerular Filtration Rate estimated through the CKD-EPI formula. Results: Among the participants (cases and controls), there was a predominance of females (59.2%) and self-declared non-white skin color (83.2%). Systemic arterial hypertension and diabetes mellitus were present in 89.8% and 46.0% of participants with CKD, respectively. FEMg was correlated with renal function biomarkers (eGFR, serum creatinine, cystatin C and 24-hour albuminuria), except for the albuminuria/creatininuria ratio (ACR) and was significantly higher in the group of patients with CKD compared to the control group, increasing as the eTFG decreased. It showed better predictive power (area under the curve 0.933) and sensitivity (88.37%) in the most advanced stage of the disease (CKD 4). The cutoff point > 4.68% determined a more accurate estimate for the reduction of GFR below 60 mL/min/1.73m2. Conclusion: This study revealed that FEMg can be a useful marker in the investigation of renal system dysfunctions, especially in relation to the progression and severity of CKD. Trial registration: The study was approved by the Ethics Committee on Human Research (HUUFMA- Maranhão -number 2.819.965).