Objective: To evaluate the associations of oral contraceptives (OC) exposure, angiotensinogen (AGT) gene polymorphism and joint effects on the risk of stroke in Chinese women.
Methods: On the basis of a prospective female cohort of contraceptive use, the first-ever-developed (FED) stroke cases, as well as, two sets of age-(± 3 years) and region-matched controls (including neighborhoods and hospitalized patients) were recruited. Between 1 July 2000 and 30 June 2009, a total of 453 FED stroke cases and 919 controls were recruited. Genotyping for polymorphisms of AGT gene was detected by Taqman method.
Results: (1) The risk of stroke gradually increased with the cumulative time of OC use in women (P < 0.0001). Compared with the non-users, the risk of hemorrhagic stroke slightly increased among those with OC use (OR = 1.83, 95%CI: 1.25 - 2.66). (2) Women with AG/GG genotypes of A-6G locus or CA/AA genotypes of C11535A locus indicated that there was a slightly reduced risk of stroke (OR = 0.78, 95%CI: 0.61 - 0.99; OR = 0.73, 95%CI: 0.56 - 0.95). (3) Women with AA genotypes of A-20C locus and AG/GG genotypes of A-6G, when incorporated with CA/AA genotypes of C11535A locus with OC, it could increase the risk of hemorrhagic stroke (OR = 1.99, 95%CI: 1.34 - 2.97; OR = 1.84, 95%CI: 1.15 - 2.94; OR = 1.73, 95%CI: 1.06 - 2.85).
Conclusion: The AGT gene polymorphisms showed that they did have an impact on the risk of stroke. And the joint effect between women using OC and AGT gene polymorphisms could slightly increase the risk of stroke.