Left Ventricle Mass Index and the Common, Functional, X-Linked Angiotensin II Type-2 Receptor Gene Polymorphism (−1332 G/A) in Patients With Systemic Hypertension

• Published in: Hypertension (Dallas, Tex. 1979) Tex. 1979), 2004-06, Vol.43 (6), p.1189-1194
• Main Authors: Alfakih, Khaled, Maqbool, Azhar, Sivananthan, Mohan, Walters, Kevin, Bainbridge, Gavin, Ridgway, John, Balmforth, Anthony J, Hall, Alistair S
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antihypertensive agents; Antihypertensive Agents - therapeutic use; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Blood Pressure - genetics; Cardiology. Vascular system; Cardiovascular system; Chromosomes, Human, X - genetics; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Female; Genetic Predisposition to Disease; Genotype; Heart Ventricles - pathology; Humans; Hypertension - drug therapy; Hypertension - genetics; Hypertension - pathology; Introns - genetics; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Organ Size; Pharmacology. Drug treatments; Point Mutation; Polymerase Chain Reaction; Receptor, Angiotensin, Type 2 - genetics
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/01.HYP.0000128532.28165.77

A common intronic polymorphism, (−1332 G/A) of the angiotensin type-2 receptor gene, located on the X-chromosome, has been reported to be functional. The aim of our study was to evaluate this polymorphism for an association with left ventricular hypertrophy. Left ventricle (LV) mass was measured in 197 patients with systemic hypertension and 60 normal volunteers using a 1.5-Tesla Philips MRI system. Genotyping was performed using a restriction enzyme digestion of an initial 310-bp polymerase chain reaction product that included the angiotensin type-2 (−1332 G/A) locus. The mean LV mass index for the male patients was 94.3±19.6 g/m (n= 125) and for the female patients was 71.2±12.0 g/m (n=72). Seventy-three (37.1%) of all patients had an elevated LV mass index, defined as the mean LV mass index for normal volunteers plus 2 SD (males 77.8±9.1 g/m, n= 30; females 61.5±7.5g/m, n= 30). Comparison of LV mass index of the A_/AA genotype (mean LV mass index= 82.4±21.1 g/m; n= 123) against that of the G_/GG genotype (mean LV mass index= 88.1±19.0 g/m; n= 89) as a continuous variable was significant by ANOVA (P = 0.044). χ Comparison between subjects with and subjects without left ventricular hypertrophy revealed an excess of the G_/GG genotype among the group with LV hypertrophy (P = 0.031). We observed an association between the angiotensin type-2 receptor (−1332 G) allele and the presence of left ventricular hypertrophy in hypertensive subjects.