GRN and acute myocardial infarction: Slightly, but not significantly, higher PGRN concentrations were found in patients with a positive history of acute myocardial infarction (AMI) (n = 5, mean age at first AMI: 53.8 ± 5.9 years) compared to patients without AMI (n = 75) (43.07 vs. 37.46 ng/mL, p = 0.06) (Figure 4).