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

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.

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.

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).

We identified 2638 patients with incident CA-SAB, of whom 713 (27.0%) had diabetes, and 26,379 matched population controls (2495 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)). Duration of diabetes 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.

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