Diabetes mellitus as a risk factor for nosocomial pneumonia and associated mortality

Abstract
Background Patients with diabetes mellitus (DM) are considered to be more susceptible to several types of infections, including community‐acquired pneumonia. However, it is not clear whether DM is a risk factor for development of hospital‐acquired pneumonia (HAP), an infection with considerable morbidity and mortality worldwide. Methods We searched PubMed for relevant publications that included data on the possible association between DM and HAP. Cohort studies, case–control studies and observational studies were included in this analysis. Two of the authors performed the literature search independently. Results We identified 84 studies designed to identify risk factors and predictors of mortality as a result of HAP. Of these, 13 studied patients in the ward or intensive care unit (ICU), 28 studied patients treated in the ICU only, and 44 studied patients with ventilator‐associated pneumonia. Only 14 considered the role of DM for this nosocomial complication. The reviewed data suggest that DM is not a risk factor for development of HAP in patients who require ICU treatment. In addition, patients with DM are not at increased risk for development of ventilator‐associated pneumonia. Moreover, DM is not a prognostic factor for mortality in patients with HAP based on data from two out of 84 identified studies that provided relevant information. Conclusions There is a relative scarcity of studies examining DM as a potential risk factor for HAP. Our analysis of the available data supports the conclusion that DM is not a risk factor for development of HAP and mortality associated with this nosocomial infection.