Type 2 diabetes and pneumonia outcomes: a population-based cohort study.

OBJECTIVE We sought to examine whether type 2 diabetes increases risk of death and complications following pneumonia and to assess the prognostic value of admission hyperglycemia. RESEARCH DESIGN AND METHODS This was a population-based cohort study of adults with a first-time hospitalization for pneumonia between 1997 and 2004 (n = 29,900) in northern Denmark. Information on diabetes, comorbidity, laboratory findings, pulmonary complications, and bacteremia was obtained from medical databases. We used regression to compute adjusted relative risks of pulmonary complications, bacteremia, and mortality rate ratios (MRRs) within 90 days following hospitalization among patients with and without type 2 diabetes. The prognostic impact of admission hyperglycemia was studied in a subcohort (n = 13,574). RESULTS In total, 2,931 (9.8%) pneumonia patients had type 2 diabetes. Mortality among diabetic patients was greater than that among other patients: 19.9 vs. 15.1% after 30 days and 27.0 vs. 21.6% after 90 days, respectively, corresponding to adjusted 30- and 90-day MRRs of 1.16 (95% CI 1.07-1.27) and 1.10 (1.02-1.18). Presence of type 2 diabetes did not predict pulmonary complications or bacteremia. Adjustment for hyperglycemia attenuated the association between type 2 diabetes and mortality. High glucose level on admission was a predictor of death among patients with diabetes and more so among those without diagnosed diabetes: adjusted 30-day MRRs for glucose level >or=14 mmol/l were 1.46 (1.01-2.12) and 1.91 (1.40-2.61), respectively. CONCLUSIONS Type 2 diabetes and admission hyperglycemia predict increased pneumonia-related mortality.