The role of diabetes mellitus in patients with bloodstream infections.

Abstract

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