Lower product of magnesium × potassium is associated with higher mortality in chronic hemodialysis patients: a cohort study

Abstract

This study aimed to investigate the Mg × K product on the mortality risk of hemodialysis patients with concomitant hypokalemia and lower magnesium levels. This was a prospective observational study of patients in a HD center in southern Taiwan. A total of 444 HD patients were divided into 5 groups by the Mg × K product: group 1, bottom quintile, median Mg × K: 7.87, IQR: 7.03–8.12 (n = 89, age: 64 ± 13 years old); group 2, median Mg × K: 9.37, IQR: 8.97–9.86 (n = 89, age:62 ± 13 years old); group 3, median Mg × K: 10.95, IQR: 10.50–11.26 (n = 89, age:64 ± 13 years old); group 4, median Mg × K: 12.30, IQR: 11.87–12.82 (n = 89, 61 ± 12 years old); and group 5, top quintile, median Mg × K: 14.92, IQR:14.07–16.23 (n = 88, 62 ± 11 years old). The patients were followed up for 2 years to determine the risk of all-cause mortality. Patients with a lower Mg × K product had more comorbidities, malnutrition-inflammation status, and a higher mortality risk. Using multivariable Cox regression analysis, a higher Mg × K [HR, 0.89; 95%CI (0.81–0.98)] was found to be an independent predictor of better survival. HD patients with a lower Mg × K product had more comorbidities, a marked malnutrition-inflammation status, and were associated with long-term mortality. A higher Mg × K value is a favorable survival factor.