Fasting hyperglycemia upon hospital admission is associated with higher pneumonia complication rates among the elderly

BACKGROUND Hyperglycemia is an independent predictor of adverse outcomes during hospitalization. In patients who have pneumonia, significant hyperglycemia is associated with poor outcomes. This study evaluates the interaction of the degree of hyperglycemia and complication rates stratified by age in non-critically ill patients admitted to the hospital for care of community-acquired pneumonia. METHODS Retrospective review of patient records coded for pneumonia. Analysis included 501 non-critically ill patients admitted to a tertiary care hospital in New York City. Data were stratified by diabetes status, age (less than 65 and 65 and over), and fasting blood glucose (FBG) within the first 24 hours of hospitalization. Among patients with no history of diabetes, FBG was stratified as "normal" [FBG /=126 mg/dl (7 mmol/l)]. The diabetic group included known diabetics regardless of FBG. The Pneumonia Severity Index (PSI) was calculated for all patients. Complications rates, hospital length of stay and mortality were compared among the groups. RESULTS In patients age 65 and older, complication rates were 16.7% in normoglycemics, 27.5% in the "mild-hyperglycemia" group, 28.6% in the "severe hyperglycemia" group, and 25.5% in those with known diabetes. The mild and severe-hyperglycemics had similar complication rates (p = 0.94). Compared to the normal group, mild and severe groups had higher rates of complications, p = 0.05 and p = 0.03, respectively. PSI tended to be higher in those over the age of 65. PSI was not significantly different when the normal, mild, severe, and known diabetes groups were compared. PSI did not predict complications for new hyperglycemia (normals' mean score 87, mild 84.7, severe 93.9, diabetics 100). Hospital mortality did not differ among groups. Length of stay was longer (p = 0.05) among mild-hyperglycemics (days = 8.4 s.e. 14.3) vs. normals (days = 6.2 s.e.6.5). CONCLUSION This study shows that FBS between 101-125 mg/dl (5.7-6.9 mmol/l) on hospital admission increases pneumonia complication rates among the elderly with no previous diagnosis of diabetes.