Diabetes and risk of community-acquired Staphylococcus aureus bacteremia: A population-based case-control study

OBJECTIVE: Patients with diabetes may experience higher risk of Staphylococcus aureus bacteremia (SAB) than patients without diabetes due to decreased immunity or coexisting morbidities. We investigated the risk of community-acquired (CA) SAB in persons with and without diabetes.

DESIGN: Using population-based medical databases, we conducted a case-control study of all adults with first-time CA-SAB and matched population controls in Northern Denmark, 2000-2011.

METHODS: Based on conditional logistic regression, we computed odds ratios (ORs) of CA-SAB according to diabetes. We further assessed whether the risk of CA-SAB differed according to various diabetes-related characteristics (e.g. duration of diabetes, glycemic control, and presence of diabetes complications).

RESULTS: We identified 2,638 patients with incident CA-SAB of which 713 (27.0%) had diabetes, and 26,379 matched population controls (2,495 or 9.5% with diabetes). Individuals with diabetes had a substantially increased risk of CA-SAB compared with population controls (adjusted OR=2.8 (95% confidence interval (CI), 2.5-3.1)). Diabetes duration of ≥10 years and poor glycemic control conferred higher risk estimates, with an adjusted OR=2.3 (95% CI, 1.9-2.7) for diabetes with Hba1c <7% (<53 mmol/mol) and an adjusted OR=5.7 (95% CI, 4.2-7.7) for diabetes with Hba1c ≥9% (≥75 mmol/mol). The risk of CA-SAB was particularly high in patient with diabetes complications: adjusted OR=5.5 (95% CI, 4.2-7.2) with presence of microvascular complications and OR=7.0 (95% CI, 5.4-9.0) with combined macro- and microvascular complications.

CONCLUSIONS: Diabetes is associated with substantially increased risk of CA-SAB, particularly among patients with diabetes of long duration, poor glycemic control, and diabetes complications.