[A study of relationship between oral contraceptives and gene polymorphism and types of stroke]

To evaluate the relationship between combined oral contraceptives (COC) taking and differential types of stroke, together with the role of the susceptive genetic factors associated with the onset of stroke in women using pills.

Case-case study was used. A total of 111 female patients with stroke were selected and with questionnaires filled in and blood samples collected. The distributions of coagulative factor V Leiden mutation (G1691-->A), prothrombin gene mutation (G20210-->A) and angiotensin converting enzyme (ACE) gene insertion/deletion(I/D) polymorphism were observed. Differences of genetic and nongenetic risk factors between hemorrhagic and ischaemic stroke were compared.

Women using pills had a higher risk developing hemorrhagic than ischaemic stroke (OR = 3.03, P < 0.05), comparing with those never used pills. The strength of association between body mass index (BMI) > or = 24 kg/m2 and ischaemic stroke was much greater than it between BMI and hemorrhagic stroke (OR = 2.99, P < 0.05). No mutation of G1691-->A or G20210-->A was found. The deletion allele frequency of ACE gene was slightly higher in ischaemic stroke group, but with no statistic significance.

The results suggested that possible association existed between the use of COC and the onset of hemorrhagic stroke, however the mutations of G1691-->A in factor V gene, G20210-->A in prothrombin gene and I/D polymorphism of ACE gene did not seem to contribute to this association.