Hyperglycemia and mortality in elderly patients with Staphylococcus aureus bacteremia

To investigate the association between hyperglycemia and in-hospital mortality in elderly patients with Staphylococcus aureus bacteremia (SAB).

We reviewed the medical records of 135 elderly patients with SAB admitted to two tertiary medical centers from January 2003 until December 2004. Patients were stratified into two groups: those with a 7-day post-SAB mean blood glucose < 170 mg/dL and those with a 7-day post-SAB mean blood glucose > or = 170 mg/dL. A stepwise logistic regression analysis was performed to determine whether the degree of hyperglycemia was a significant predictor of mortality.

Seventy-four (54.8%) patients had methicillin-resistant Staphylococcus aureus bacteremia. During the follow-up period from admission until discharge, 36 (26.7%) patients died. Twenty-one (21.4%) of 98 patients with a 7-day post-SAB mean blood glucose < 170 mg/dL died, while 15 (40.5%) of 37 patients with a 7-day post-SAB mean blood glucose > or = 170 mg/dL expired. Multivariate analysis identified 3 independent determinants of death: Simplified Acute Physiology Score (SAPS) score at onset of SAB > 45 (OR 5.3, 95% CI {1.8, 15.5}, P = 0.002), a 7-day post-SAB mean blood glucose > or = 170 mg/dL (OR 3.3, 95% CI {1.2, 9.2}, P = 0.03), and altered mental status at the onset of SAB (OR 7.8, 95% CI {2.5, 23.9}, P = 0.0003).

Hyperglycemia is an important marker of increased mortality among hospitalized elderly patients with SAB.