title: Left-ventricular structure in the Southall And Brent REvisited (SABRE) study: explaining ethnic differences.
abstract: Cardiometabolic risk is elevated in South Asians and African Caribbeans compared with Europeans, yet whether this is associated with ethnic differences in left-ventricular structure is unclear. Conventional M-mode or 2-dimensional echocardiography may be misleading, because they calculate left-ventricular mass and remodeling using geometric assumptions. Left-ventricular structure was compared in a triethnic population-based cohort using conventional and 3-dimensional echocardiography on 895 individuals (aged 55-85 years; 427 European, 325 South Asian, 143 African Caribbean). Left-ventricular mass was indexed, and left-ventricle remodeling index and relative wall thickness were calculated. Anthropometry, blood pressure, and fasting bloods were measured. Three-dimensional left-ventricular mass index did not differ between Europeans (mean ± SE, 29.8 ± 0.3 g/m(2.7)) and African Caribbeans (29.9 ± 0.5 g/m(2.7); P=0.9), but it was significantly lower in South Asians (28.1 ± 0.4 g/m(2.7); P<0.0001) compared with Europeans. These findings persisted on multivariate adjustment. In contrast, conventional left-ventricle mass index was significantly higher in African Caribbeans (46.4 ± 0.9 g/m(2.7)) than in Europeans (41.9 ± 0.5 g/m(2.7); P<0.0001). Left-ventricle remodeling index was the highest in African Caribbeans and the lowest in South Asians. Relative wall thickness was also higher in African Caribbeans, but no different in South Asians, compared with Europeans. Differences in left-ventricle remodeling index were attenuated by adjustment for cardiometabolic factors between African Caribbeans and Europeans only. In conclusion, left-ventricular mass is lower in South Asians and equivalent in African Caribbeans compared with Europeans, even when cardiometabolic risk factors are accounted for. Left-ventricular remodeling rather than hypertrophy may explain the increased risk of heart failure in people of African Caribbean origin.
authors.affiliation: International Centre for Circulatory Health, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, and Imperial College Healthcare National Health Service Trust, London, UK. chloe.park@imperial.ac.uk
authors.forename: Chloe M
authors.initials: CM
authors.lastname: Park
authors.forename: Katherine
authors.initials: K
authors.lastname: March
authors.forename: Arjun K
authors.initials: AK
authors.lastname: Ghosh
authors.forename: Siana
authors.initials: S
authors.lastname: Jones
authors.forename: Emma
authors.initials: E
authors.lastname: Coady
authors.forename: Claire
authors.initials: C
authors.lastname: Tuson
authors.forename: Darrel
authors.initials: D
authors.lastname: Francis
authors.forename: Jamil
authors.initials: J
authors.lastname: Mayet
authors.forename: Therese
authors.initials: T
authors.lastname: Tillin
authors.forename: Nish
authors.initials: N
authors.lastname: Chaturvedi
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology*; D044383:Black People / Q000208:ethnology*; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D006113:United Kingdom; D020257:Ventricular Remodeling; D044465:White People / Q000208:ethnology*