Hyperglycemia in diabetics and non-diabetics: Effect on the risk for and severity of pneumococcal pneumonia

Summary Objectives We sought to determine whether poor glucose control among diabetics is associated with increased risk for pneumococcal pneumonia and whether elevated admitting plasma glucose (APG) levels are associated with increased severity of this infection in diabetic and non-diabetic patients. Methods We compared hemoglobin A 1c (HbA 1c ) in diabetics who had pneumococcal pneumonia with diabetic case–controls who did not have pneumonia. In patients with pneumococcal pneumonia, we related APG to disease severity as determined by SMART-COP score, need for ICU admission, and mortality at 7 and 30 days. Results Fifty-three of 233 patients with pneumococcal pneumonia (22.7%) were diabetic. Diabetics with pneumonia had poorer glycemic control than diabetic case–controls (HbA 1c 8.2% vs. 7.2%, respectively, P Conclusions Poor glycemic control predisposes diabetics to pneumococcal pneumonia but, among diabetics, the degree of hyperglycemia at admission is not associated with increased disease severity. In contrast, among non-diabetics with pneumococcal pneumonia, hyperglycemia is a marker for severe disease and increased mortality, perhaps reflecting massive release of cytokines and glucocorticosteroids in overwhelming infection.