Effect of inflammatory factors on myocardial infarction

Abstract Background: Cohort studies have increasingly shown associations between inflammatory markers and myocardial infarction (MI); however, the specific causal relationships between inflammatory markers and the development of MI remain unclear. Methods and results: By utilizing publicly accessible genome-wide association studies, we performed a two-sample Mendelian randomization (MR) analysis to explore the causal associations between inflammatory markers and myocardial infarction (MI). A random-effects inverse-variance weighted method was used to calculate effect estimates. Neutrophil count was found to increase the risk of MI (odds ratio [OR] = 1.08; 95% confidence interval [CI], 1.00–1.17; p = 0.04). C-reactive protein levels correlated positively with MI. No associations were observed with IL-1 beta, IL-6, IL-18, procalcitonin, TNF-α, total white cell count, or neutrophil percentage of white cells. Neutrophil count and C-reactive protein were inversely associated with lactate dehydrogenase: neutrophil cell count (OR 0.95; 95% CI, 0.93–0.98; p<0.01) and C-reactive protein (OR 0.96; 95% CI, 0.92–1.00; p = 0.02). No associations of MI with myoglobin, troponin I, and creatine kinase-MB levels were found. Conclusions: This two-sample MR analysis revealed a causal positive association of MI with neutrophil count, C-reactive protein level, and the myocardial injury marker lactate dehydrogenase. These results indicate that monitoring C-reactive protein and neutrophil counts may be useful in management of MI patients.