Related Experiment Videos
Association between angiotensin II type I receptor polymorphism and resting hemodynamics in black and white youth
Paule Barbeau1, Anita Kulharya, Gregory Harshfield
1Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta 30912, USA. pbarbeau@mail.mcg.edu
Objectives:
An angiotensin II type I receptor polymorphism (AGTR1/A1166C) was previously found to be associated with hypertension. The purpose of this study was to investigate the relationship between this polymorphism and resting measures of hemodynamics in normotensive youth.
Design:
Subjects were 41 Whites (mean +/- SD: 18 +/- 3 y old, 26 males) and 73 Blacks (19 +/- 2 y old, 55 males) with a positive family history of hypertension.
Methods:
Hemodynamic measures included resting systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR).
Results:
Allele frequencies were significantly different (chi2 = 14.10, P < or = .001) between Whites and Blacks (.23 vs .06 for the C allele, respectively). For all subsequent analyses, subjects were categorized into two genotype groups, carriers and non-carriers of the C allele, because only two Whites and no Blacks were homozygous for the C allele. Genotype frequencies were significantly different (chi2 = 12.66, P < or = .0011) between Whites and Blacks (.41 vs .12 for the carriers, respectively). Among Whites, univariate analyses of covariance, using body mass index and age as covariates, indicated that carriers of the C allele compared to non-carriers, had a higher DBP (61.6 +/- 6.7 vs 57.8 +/- 6.2 mm Hg, P < or = .05) and HR (68.0 +/- 10.5 vs 61.1 +/- 8.1, P < or = .05). Genotype was not associated with resting hemodynamic measures in Blacks (all P values > .05).
Conclusions:
These results are consistent with findings that have typically involved White adults, and demonstrate that the renin system does not seem to play as great a role in BP control in Blacks as it does in Whites.