The role of diabetes mellitus in patients with bloodstream infections

Abstract

Background: Since diabetes mellitus predisposes to infection, we evaluated whether diabetes increases the risk of bloodstream infection and worsens its outcome.

Methods: During a 4-year period 71 diabetic and 252 non-diabetic patients with bloodstream infection were included. Risk factors for death were assessed by univariate and multivariate analysis.

Results: Bloodstream infection was more frequent in diabetics than in non-diabetics (25.8/1000 admissions vs. 5.8/1000 admissions, p <0.0001). Urinary tract infection was the predominant source, and Escherichia coli the most frequent microorganism in both groups. Klebsiella pneumoniae was more frequent in diabetics than in non-diabetics (18% vs 5%, p <0.001). Whereas sepsis of unknown origin was more common in diabetics (14% vs. 6%, p <0.05), catheter-related bloodstream infection predominated in non-diabetics (3% vs 10%, p <0.05). Secondary septic foci (p <0.05) and disseminated intravascular coagulation (p <0.05) were more frequent in diabetics. The in-hospital mortality rate was similar in the two groups (18% vs. 14%). Univariate analysis (RR [CI 95%]) in diabetics revealed glycaemia >20 mmol/L (3.9 [1.7-22]), ICU stay (7.1 [2-25]), mechanical ventilation (8.4 [1.2-57]) and chronic renal/hepatic failure (8.2 [1.6-43]) as significant risk factors. Hyperglycaemia (4.3 [3.4-5.2]) and ICU stay (3.3 [1.9-4.9]) remained significant in multivariate analysis.

Conclusions: Diabetics had a 4.4-fold higher risk of bloodstream infection, were more prone to sepsis of unknown origin and had more septic complications than non-diabetics. The mortality rate was similar in the two groups.