Fasting blood glucose levels identify high-risk individuals across the ACS spectrum

Elevated blood glucose at hospital admission, and elevated fasting blood glucose levels during admission, have been shown to predict worse outcome among patients with STEMI, however, the contribution of glucose levels to risk predictive algorithms involving patients with acute coronary syndromes (ACS) remains unclear.

Admission and fasting glucose levels were available for 13 526 patients enrolled in the Global Registry of Acute Coronary Events (GRACE). This included patients with STEMI, NSTEMI and unstable angina admitted to hospital between April 1999 to December 2005 from 106 hospitals in 14 countries.

In-hospital and 6 month mortality was calculated and correlated against the presence and degree of glucose elevation on admission and in a fasting sample during admission. Researchers found that patients who had higher fasting glucose levels were more often female, had a higher Killip class, and had a history of hypertension, previous stroke / TIA or peripheral vascular disease. 39.7% of patients were newly diagnosed as diabetic.

Elevated admission and fasting glucose levels independently predicted higher in-hospital mortality, however 6 month mortality only appeared to correlate with certain levels of fasting glucose elevation (see table) and did not correlate with glucose levels on admission. Congestive cardiac failure, cardiogenic shock and major bleeding complications also appeared to occur more frequently among patients with elevated glucose levels.

Degree of fasting

glucose elevation (mg/dL)

In-hospital mortality (OR vs patients with <100mg/dL)

6 month mortality (OR vs patients with <100mg/dL)

100-125 (Impaired Glucose Tolerance)

1.51 [1.12 to 2.04]

1.18 [0.87 to 1.58]

126-199 (Diabetes)

2.20 [1.64 to 2.60]

1.71 [12.5 to 2.34]

200-299

5.11 [3.52 to 7.43]

1.08 [0.60 to 1.95]

>300

8.00 [4.76 to 13.5]

2.93 [1.33 to 6.43]

These data extend the relationship between elevated fasting glucose level and adverse outcome to the wider spectrum of ACS. Fasting glucose appeared to be a more robust independent marker of adverse outcome than admission glucose, which may represent a severe stress response rather than disturbed glucometabolism. Overall, these data reinforce the importance of categorising diabetic patients with ACS as high risk.

ยท Sinnaeve P, Steg G, Fox K et al. Association of elevated fasting glucose with increased short-term and 6-month mortality in ST-segment elevation and non-ST segment elevation acute coronary syndromes. The Global Registry of Acute Coronary Events. Arch Intern Med. 2009;169(4):402-9