Comparison of inflammatory biomarkers between diabetic and non-diabetic patients with unstable angina.

Background: Studies comparing inflammatory activity between diabetic and non-diabetic individuals with acute coronary syndrome are scarce, and none including only patients with unstable angina (UA) has been published to date.

Objective: We compared serum C-reactive protein (CRP), and interleukin-6(IL-6) between diabetic and non-diabetic patients with unstable angina (UA) to determine if difference in inflammatory activity is responsible for a worse prognosis in diabetic patients. We also evaluated the correlation between inflammatory markers and the metabolic profile in diabetic patients and the correlation between inflammatory response and in-hospital outcomes: death, acute myocardial infarction, congestive heart failure, and length of stay in hospital.

Methods: A prospective cohort study of 90 consecutive patients admitted to a chest pain unit with UA and divided into two groups, diabetic and non-diabetic. Serum CRP, IL-6, metabolic profile and leukocyte count were measured at hospital arrival.

Results: Forty-two patients (47%) were diabetic (age 62+/-9) vs. 48 (53%) non-diabetic (age 63+/-12). No differences between median C-reactive protein (1.78 vs. 2.23 mg/l,p=0.74) and interleukin-6 (0 vs. 0 pg/ml,p=0.31) were found between the two groups. There was a positive correlation between CRP and total cholesterol (rs = 0.21,p = 0.05), CRP and LDL-cholesterol (rs=0.22,p=0.04) and between CRP and leukocyte count (rs = 0.32, p = 0.02) in both groups. No associations were found between inflammatory markers and in-hospital outcomes.

Conclusion: We found no difference in inflammatory activity between diabetic and non-diabetic patients with UA, suggesting that this clinical condition may result in balanced inflammatory activity between the two groups and increase acute-phase proteins independently of metabolic state.