Reduction in Serum Magnesium Levels and Renal Function Are Associated with Increased Mortality in Obese COVID-19 Patients.

Several studies provide evidence that obesity is a significant risk factor for adverse outcomes in coronavirus disease 2019 (COVID-19). Altered renal function and disturbances in magnesium levels have been reported to play important pathophysiological roles in COVID-19. However, the relationship between obesity, renal function, circulating magnesium levels, and mortality in patients with COVID-19 remains unclear. In this retrospective cohort study, we characterized 390 hospitalized patients with COVID-19 that were categorized according to their body mass index (BMI). Patients were clinically characterized and biochemical parameters, renal function, and electrolyte markers measured upon admission. We found that in patients who died, BMI was associated with reduced estimated glomerular filtration rate (eGFR, Rho: −0.251, p = 0.001) and serum magnesium levels (Rho: −0.308, p < 0.0001). Multiple linear regression analyses showed that death was significantly associated with obesity (p = 0.001). The Cox model for obese patients showed that magnesium levels were associated with increased risk of death (hazard ratio: 0.213, 95% confidence interval: 0.077 to 0.586, p = 0.003). Thus, reduced renal function and lower magnesium levels were associated with increased mortality in obese COVID-19 patients. These results suggest that assessment of kidney function, including magnesium levels, may assist in developing effective treatment strategies to reduce mortality among obese COVID-19 patients.

Renal function, serum magnesium levels and mortality in COVID-19 patients with type 2 diabetes.

Patients with type 2 diabetes (T2D) and Latin American subjects in particular are at an increased risk of developing severe COVID-19 and mortality. Altered renal function and lower magnesium levels have been reported to play important roles in the pathophysiology of T2D. The aim of the study was to investigate the relationship between renal function, serum magnesium levels and mortality in T2D patients with COVID-19. In this retrospective study, we characterized 118 T2D and non-diabetic subjects hospitalized with COVID-19. Patients were clinically characterized and electrolyte, renal function and inflammatory markers were evaluated. Patients were grouped according to their estimated glomerular filtration rate (eGFR <60 mL/min per 1.73 m2). T2D patients had lower eGFR and serum magnesium levels when compared to non-diabetics (59.7 ± 32.8 vs. 78.4 ± 33.8 mL/min per 1.73 m2, P = 0.008 and 1.9 ± 0.3 vs. 2.1 ± 0.3 mEq/L, P = 0.012). Survival was worse in T2D patients with eGFR levels less than 60 mL/min per 1.73 m2 as estimated by Kaplan-Meier analyses (log-rank test <0.0001). The Cox model for T2D patients showed that eGFR (HR 0.970, 95% CI 0.949 to 0.991, P = 0.005) and magnesium (HR 8.025, 95% CI 1.226 to 52.512, P = 0.030) were associated with significantly increased risk of death. Reduced eGFR and magnesium levels were associated with increased mortality in our population. These results suggest that early assessment of kidney function, including magnesium levels, may assist in developing effective treatment strategies to reduce morbidity and mortality among Latin American COVID-19 patients with T2D.