Diabetes mellitus and pyogenic liver abscess: risk and prognosis.

BACKGROUND Pyogenic liver abscess (PLA) is a rare, life-threatening disease with an increasing rate of incidence. Case reports from East Asia suggest that diabetes mellitus is an important risk factor, but formal evidence is limited. METHODS We performed a case-control study with participants drawn from the entire population of Denmark. Cases of PLA were defined as occurring in all patients who received a first-time diagnosis of PLA on hospital discharge between 1977 and 2002, as identified in the nationwide Danish National Patient Registry. Fifty sex- and age-matched population control subjects were selected for each patient with PLA. We computed the relative risk of PLA associated with diabetes using conditional logistic regression and controlling for major potential confounders. We further examined whether diabetes increased the relative risk of death until 30 days after hospital discharge among patients with PLA. RESULTS We identified 1448 patients who experienced a first hospitalization for PLA during the study period (median age, 64 years; male sex, 54.2%). Persons with diabetes had a 3.6-fold increased risk of experiencing PLA, compared with population control subjects (adjusted relative risk, 3.6; 95% confidence interval, 2.9-4.5]. In addition, patients with PLA who had diabetes had a higher 30-day postdischarge mortality rate, compared with patients with PLA who did not have diabetes (24.8% vs. 18.0%). After controlling for other prognostic factors, the relative risk of death for patients with PLA and diabetes was 1.3 (95% confidence interval, 0.9-2.1). CONCLUSIONS Diabetes is a strong, potentially modifiable risk factor for PLA. PLA is associated with a similarly poor prognosis for patients with diabetes and for other patients.