Inflammation-sensitive plasma proteins and incidence of myocardial infarction in men with low cardiovascular risk

Objective - Myocardial infarction (MI) is sometimes experienced by individuals without any traditional risk factor. This prospective study explored whether incidence of MI in nonsmoking, nondiabetic men with normal blood pressure and serum lipids is related to inflammation-sensitive plasma proteins (ISPs). Methods and Results - Five ISPs (alpha1-antitrypsin, haptoglobin, ceruloplasmin, fibrinogen, orosomucoid) were analyzed in 6075 men, 47 +/- 3.6 years old. A low-risk group (no traditional risk factor, n = 1108) and a high-risk group (greater than or equal to2 major risk factors, n = 1011) were defined. Incidence of MI (n = 227) was monitored over 18.1 +/- 4.3 years of follow-up. In the low-risk group, the age-adjusted relative risks (RRs) were 1.00 (reference), 1.9 (95% CI, 0.8 to 4.2), 1.8 (95% CI, 0.6 to 5.4), and 2.9 (95% CI, 1.05 to 8.1), respectively, for men with 0, 1, 2 and greater than or equal to 3 ISPs in the top quartile (trend: P = 0.03). In this group, the increased risk was observed only after greater than or equal to 10 years of follow-up. In the high-risk group, the age-adjusted RRs were 1.00, 1.4 (95% CI, 0.9 to 2.2), 1.9 (95% CI, 1.2 to 3.1), and 2.0 ( 95% CI, 1.3 to 3.1), respectively, for men with 0, 1, 2, and greater than or equal to 3 ISPs in the top quartile (trend: P = 0.0004). Conclusion - Incidence of MI in nonsmoking, nondiabetic men with normal blood pressure and lipids was related to ISPs. The causes for this relationship remain to be explored.