Juhan-Vague I, Morange PE, Frere C, Aillaud MF, Alessi MC, Hawe E, Boquist S, Tornvall P, Yudkin JS, Tremoli E, Margaglione M, Di Minno G, Hamsten A, Humphries SE, HIFMECH Study Group. HIFMECH Study Group. The plasminogen activator inhibitor-1 -675 4G/5G genotype influences the risk of myocardial infarction associated with elevated plasma proinsulin and insulin concentrations in men from Europe: the HIFMECH study. J Thromb Haemost. 2003;1(11):2322-9.

Although the potential role of plasminogen activator inhibitor-1 (PAI-1) in the development of coronary artery disease is strongly supported by its biological characteristics, results of clinical studies remain controversial. OBJECTIVES: To investigate whether plasma PAI-1 concentrations and the -675 4G/5G polymorphism located in the PAI-1 gene could constitute risk markers for myocardial infarction (MI). PATIENTS AND METHODS: We used a European case-control study, the HIFMECH study, comparing 598 men with MI and 653 age-matched controls. RESULTS: Insulin resistance explained a major part of the variation in PAI-1 (24%) whereas inflammation had only a minor contribution (0.01%). For both cases and controls plasma PAI-1 concentrations were significantly higher in the North than the South, and in both regions were higher in individuals with MI compared with control subjects [overall odds ratio (OR) for a 1 SD increase=1.54, 95% confidence interval (CI) 1.34, 1.77]. This difference was observed in all the centers studied. Overall, the difference between cases and control subjects remained significant after controlling for inflammation variables (OR=1.30, 95% CI 1.08, 1.57), but lost significance after controlling for insulin resistance variables (OR=1.17, 95% CI 0.98, 1.40). The 4G allele was associated with significantly higher PAI-1 levels in cases but not controls and, taken independently, did not modify the risk of MI (P=0.9). However, a significant interaction was observed with both insulin or proinsulin and the risk of MI (P=0.05 and 0.02, respectively), but not with triglycerides or body mass index (BMI). The insulin or proinsulin effect on risk was observed only in the carriers of the 4G/4G genotype. This interaction appeared not to be mediated by plasma PAI-1 antigen concentrations (P=0.01 and 0.02 after adjustment for PAI-1 plasma levels). The interaction with proinsulin but not insulin remained statistically significant after further adjustment for other factors associated with insulin resistance (triglycerides and BMI) and C-reactive protein (P=0.01). CONCLUSION: This study suggests that PAI-1 has a role in risk of MI in the presence of underlying insulin resistance. A significant interaction between insulin or proinsulin and the -675 4G/5G polymorphism was observed in risk for MI. The mechanisms for these interactions remain to be determined.

Share on: