Risk of community-acquired pneumococcal bacteremia in patients with diabetes: a population-based case-control study.

Objective: We conducted this population-based case-control study to examine whether diabetes is associated with an increased risk of community-acquired pneumococcal bacteremia.
Research Design and Methods: We included 598 cases in the North Jutland County Bacteremia Registry, Denmark, with residence in the county and a first hospitalization for community-acquired pneumococcal bacteremia from 1992 through 2001. Ten sex- and age-matched population control subjects per case were selected, using a unique personal identifier. Diabetes was determined by record linkage with the County Prescription Database (for prescriptions for antidiabetic drugs) and the Hospital Discharge Registry (for previous hospitalizations with diabetes or diabetic complications). We performed conditional logistic regression to estimate odds ratios (ORs) for pneumococcal bacteremia among diabetic and nondiabetic persons, with adjustment for a range of comorbid diseases considered to be risk factors for pneumococcal infection.
Results: The crude OR for pneumococcal bacteremia in persons with diabetes was 1.9 (95% CI 1.4-2.6). After adjustment for comorbidity, the OR decreased to 1.5 (95% CI 1.1-2.0). The impact of diabetes on the risk for pneumococcal bacteremia was most pronounced in adults aged 40 years and younger (adjusted OR 4.2, 95% CI 1.1-16.7) and in persons without any other coexisting morbidity (adjusted OR 2.3, 95% CI 1.3-3.9). Under the assumptions that the association was causal and that there is a 5% overall prevalence of diabetes in our study population, 24 of 1,000 admissions with incident pneumococcal bacteremia may be attributed to diabetes.
Conclusions: Diabetes seems to be a risk factor for community-acquired pneumococcal bacteremia.