Background: The angiotensin-converting enzyme 1 (ACE1) gene has been extensively studied in stroke, yet generating conflicting results. The goal of our study was thus to clarify the influence of the ACE1 on the risk of suffering an ischaemic stroke (IS).
Methods: We genotyped the rs4341 (in linkage disequilibrium with the I/D polymorphism) of the ACE1 gene in 531 patients with IS and 549 healthy controls, and the rs1799752 (I/D polymorphism) in a subset of 68 patients with IS and 27 controls. We also performed functional studies by measuring serum ACE protein levels and enzymatic activity in 27 controls, 68 patients with IS at baseline and 35 patients with IS 24 h after onset of stroke symptoms.
Results: There was no association of the ACE1 variant with IS, although it affected ACE protein levels (P = 0.001). Indeed, patients with IS showed lower ACE levels than controls in the acute phase (115.9 } 38.9 vs. 174.1 } 56.1 ng/ml, P < 0.001), but not in the chronic phase (168.2 } 51.2, P = 0.673), and ACE protein levels did not differ between IS etiologies. Similar results were found for ACE activity.
Conclusions: The D allele of the ACE1 I/D and ACE protein levels was not associated with a higher risk of IS in Spanish individuals.