Blood pressure and the M235T polymorphism of the angiotensinogen gene

The angiotensinogen gene locus (1q42-43) has been linked to hypertension in affected relative-pair studies (including a previous UK study), but the role of the Met-->Thr polymorphism at position 235 remains controversial. Using this marker, we investigated the relationship between angiotensinogen genotype and blood pressure in two data sets from the East Anglia region of the United Kingdom. Two hundred twenty-three untreated hypertensive and 187 normotensive control subjects were recruited through local general practices. Blood pressure (including pretreatment measurements in the hypertensive group), age, sex, body mass index, alcohol consumption, cholesterol level, and angiotensinogen genotype were recorded for all subjects. The influence of angiotensinogen genotype on blood pressure was assessed with a general linear model ANOVA with adjustment for age, sex, body mass index, and alcohol consumption. There was no evidence for an association between angiotensinogen genotype and blood pressure level in either the hypertensive or normotensive data set. Angiotensinogen genotype did not influence blood pressure in subjects aged < 50 years, women, or those with a body mass index < 26 kg/m(2). We conclude that the angiotensinogen Met-->Thr polymorphism is not a marker for blood pressure level in these East Anglian subjects. Further studies are required to confirm the involvement of the Iq locus in the development of hypertension in UK subjects and to delineate the functional variant(s) in this chromosomal region that influences blood pressure.