The association between serum magnesium levels and community-acquired pneumonia 30-day mortality.

Background: Community acquired pneumonia (CAP) is a common illness affecting hundreds of millions worldwide. Few studies have investigated the relationship between serum magnesium levels and outcomes of these patients. We aimed to study the association between serum magnesium levels and 30-day mortality among patients with CAP.
Methods: Retrospective overview of patients hospitalized with CAP between January 1, 2010 and December 31, 2016. Participants were analyzed retrospectively in order to identify the risk factors for a primary endpoint of 30-day mortality. Normal levels of magnesium levels in our laboratory varies between 1.35 and 2.4 mg/dl.
Results: 3851 patients were included in our cohort. Age > 75 years, blood urea nitrogen (BUN) > 20 mg/dl, hypoalbuminemia, and abnormal levels of magnesium were all associated with increased risk of 30-day mortality. Normal magnesium levels were associated with the lowest mortality rate (14.7%). Notably, within the normal levels, high normal magnesium levels (2-2.4 mg/dl) were correlated with higher mortality rates (30.3%) as compared to levels that ranged between 1.35-2 mg/dl (12.9%). Hypomagnesemia and hypermagnesemia were both associated with excess of 30-day mortality, 18.4 and 50%, respectively.
Conclusion: Hypomagnesemia and hypermagnesemia on admission were associated with an increased rate of 30-day mortality among adult patients hospitalized with CAP. Interestingly, magnesium levels within the upper normal limits were associated with higher mortality.