Abstract 2528: The WW Domain Binding Protein 1: a Potential Gene Contributing to Arterial Stiffness in Hypertensives
Background: Regulation of arterial structure and function has a strong genetic component. Pulse pressure (PP) which is directly related to arterial stiffness, is considered a crude measure of arterial function and PP/Stroke volume ratio (PP/SV) is consider an index of total arterial compliance and a predictor of cardiovascular morbid. The WW domain binding protein 1 (WBP1) gene is located on chromosome 2 (2p12). Although the function of this protein has not been determined, several studies have shown the effect of WW domain binding protein on the regulation of the epithelial Na channel, especially in Liddle’s syndrome.
Objective: to evaluate the genotype distribution of WBP1 in Hispanics and African-Americans (AA) and its relationship with an index of arterial compliance.
Methods: All individuals in this study were participants of the NHLBI Family Blood Pressure Program. All subjects were genotyped for the WBP1 and had echocardiogram measurements.
Results: 980 Hispanics (63% normotensives, 37% hypertensives) and 1338 AA (29% normotensives, 71% hypertensives) were studied. The genotype distribution for Hispanics was CC = 586 (60%); CT = 345 (35%) and TT = 49 (5%), thus, T allele = 394; in AA the distribution was CC = 58 (4.33%); CT = 419 (31.3%) and TT = 861 (64.3%), thus, C allele = 477. Genotype distributions were in Hardy-Weinberg equilibrium. In hypertensive Hispanics, subjects with CC genotype had significantly lower PP/SV (0.84 ± 0.25 vs 0.96 ± 0.29 mmHg/ml, p < 0.05) and significantly higher SV (78 ±16 vs 72 ±13 ml, p < 0.05) compared to subjects with T allele. In hypertensive AA, subjects with C allele had significantly lower PP/SV (0.88 ± 0.26 vs 0.91 ± 0.29 mmHg/ml, p < 0.05) and significantly higher SV (80 ±16 vs 78 ± 14 ml, p < 0.05) compared to subjects with TT genotype. No significant differences were observed for age, BMI, blood pressure, pulse, and left ventricular mass index. No significant differences were observed in normotensives. Chi square analysis showed no significant differences in the number of hypertensives, diabetic, subjects on anti-hypertensive or anti-diabetic drugs were observed in the genotyped groups.
Conclusions: This study shows a potential effect of WW domain binding proteins on arterial structure and function of hypertensive subjects.