Comparison of Health Outcomes and Nephrotoxicity for Diabetic and Non-Diabetic Patients Hospitalized for MRSA Bacteremia

Background: Type 2 diabetes mellitus is characterized by a progressive worsening of glycemic control. This may predispose diabetics to acquiring and experiencing complications from an array of superficial and systemic infections, including methicillin-resistant Staphylococcus aureus (MRSA) infections.

Objective: The aim of the present study was to compare healthcare outcomes and nephrotoxicity for diabetics and non-diabetics admitted to the hospital with MRSA bacteremia.
Methods: Patient demographics, laboratory values, site(s) of infection, comorbidities, and medication use were obtained by retrospective chart review. Hospital mortality was the primary outcome, while nephrotoxicity, hospital length of stay (LOS), and intensive care unit (ICU) LOS were secondary outcomes. Peak serum creatinine (SCr_peak ) was measured to compare nephrotoxicity between groups. Chi-square and Student’s t-test were used to compare dichotomous and numeric variables, respectively.
Results: Of the 87 patients who met study criteria, 74% were male, 43% were diabetic, and 90% had a CrCl >50 ml/min. Diabetic and non-diabetic patients were similar with regard to most baseline characteristics except mean age (48 vs. 43 years, p=0.03) and Charleson Co-morbitidty Index (3.4 vs. 2.3, p<0.01). The most common sources of MRSA bacteremia were, skin or soft tissue (45%) and pulmonary (22%) sites, followed by osteomyelitis (14%), endocarditis (9%), genitourinary (7%), and catheter-related (3%) infections. Medication use was similar between groups with 87% of patients receiving vancomycin 1 gram every 12 hours initially, 71% receiving at least one vancomycin dose adjustment, and 28% receiving concomitant aminoglycosides. There were no significant differences with respect to mortality [1(3%) vs. 5(10%) deaths, p = 0.5], SCr_peak (1.47 vs 1.46 mg/dl, p = 0.36), LOS (19.5 vs. 23 days, p = 0.85), and ICU LOS (3.3 vs 4.5 days, p = 0.5).
Conclusions: Diabetics and non-diabetics admitted to the hospital with MRSA bacteremia experience similar health outcomes including mortality, nephrotoxicity, LOS, and ICU LOS.