Association between magnesium depletion score and all-cause and cause-specific mortality in patients with diabetic kidney disease.

BACKGROUND

The prognostic value of Magnesium Depletion Score (MDS) in Diabetic Kidney Disease (DKD) patients is still unclear. This study aimed to determine the associations between MDS and long-term mortality in DKD population.

METHODS

Data were obtained from the National Health and Nutrition Examination Survey (NHANES III). MDS is calculated from four specific scoring items: estimated glomerular filtration rate (eGFR), heavy drinking, use of proton pump inhibitors (PPI), and use of diuretics. Multivariate Cox proportional hazards regression models was employed to explore the association between MDS and all-cause and cause specific mortality, with emphasis on age-specific analysis.Mediation analysis explored if metabolic indices mediate the relation between MDS and mortality. Sensitive analyses were performed to check the robustness of the main findings.

RESULTS

3,179 patients with DKD were included in this study, with 1,698 females and 1,481 males. The multivariate Cox regression analyses showed higher MDS were significantly associated with the all-cause mortality of DKD population [MDS ≥ 3: adjusted hazard ratio (HR):1.932, 95% confidence interval (CI): 1.339-2.787,p < 0.001]. Meanwhile, the trend was also significant in cardiovascular mortality of the DKD population (MDS ≥ 3: HR = 3.688, 95%CI: 1.702-8.577,p < 0.001). Heavy drinking was the most influential factor among the four MDS scoring items that affects mortality outcomes. Mediation analysis showed increased MDS could slightly improve metabolic levels, but the improvement was insufficient to reverse the mortality outcome in DKD patients. Subgroup analysis manifested that the result was more applicable for patients over 60. The result of the sensitive analysis confirmed the robustness of the main conclusion.

CONCLUSIONS

Our study highlights the clinical prognostic value of MDS in predicting the survival of the DKD population, especially among patients over 60. The findings imply that reducing alcohol consumption and performing routine cardiovascular health assessments for DKD patients with MDS > 2 are important for prolonging DKD patients' survival time.