Association between serum apolipoprotein C_II concentration and coronary heart disease

Background. Apolipoprotein (Apo) C_II plays an essential role in the metabolism of triglyceride-rich lipoproteins (TRLs) by activating lipoprotein lipase. Several studies have suggested that an abnormal concentration of Apo C_II may serve as a marker for deficient TRL metabolism, a possible cause of coronary heart disease (CHD). The aim of the present study was to evaluate the association between Apo C_II and the presence of CHD. Methods. A case-control study comparing 352 CHD patients and 395 controls was performed. Demographic, clinical, and laboratory characteristics were determined. Results. The CHD patients had a higher mean concentration of Apo C_II than controls (5.3 mg/dl compared with 4.2 mg/dl, P < 0.001). Elevated serum Apo C_II concentration was associated with CHD presence after adjustment for cardiovascular risk factors. The risk factor-adjusted odds ratio (OR) for CHD was 1.60 (95% CI: 1.31-1.94) per 1 mg/dl increment in Apo C_II, compared with a risk factor-adjusted OR of 1.05 (95% CI: 0.85-1.32) per 40 mg/dl increment in triglyceride concentration. Conclusion. Increased serum concentration of Apo C_II may represent a more sensitive marker of CHD than high serum concentration of triglycerides. Confirmation in cohort studies in required to establish or refute the role of elevated serum Apo C_II as a risk factor for CHD.