Poor sleep quality associated with higher left ventricular mass in African/Caribbean and South Asian adults

Abstract Background: Poor sleep quality is associated with increased cardiovascular risk, although its relationship with left ventricle (LV) structure is poorly understood and ethnic differences in the relationship between sleep and LV structure have not been studied. We investigated the association between poor sleep quality and LV structure in a tri-ethnic cohort. Methods: A total of 1284 participants were analysed from the Southall and Brent Revisited (SABRE) study (age=49.9{+/-} 6.2y; male 75.9%, Europeans (EU)=615, South Asians (SA)=457, African/African-Caribbean (AC)=212). A composite sleep quality score was calculated, and LV structure was measured using echocardiography. Associations between sleep quality and LV mass indexed to height1.7 (LVMi), relative wall thickness (RWT) and LV end-diastolic volume indexed to height1.7 (LVEDVi) were estimated using multivariable linear regression with adjustment for demographic and lifestyle factors across three models. Analyses were performed in the whole cohort and stratified by ethnicity. Results: Compared with those who reported very good sleep quality, participants with poorer sleep quality had higher LVMi (4.8 (95% CI 1.4; 8.2)g/(m1.7*unit sleep score); p=0.006). When stratifying by ethnicity, the association between sleep quality and LVMi was unconvincing in EU (1.9(-3.5, 7.3)g/(m1.7*unit sleep score); p=0.493), whereas poor sleep was associated with higher LVMi in AC and SA participants (9.1(1.3;16.8)g/(m1.7*unit sleep score); p=0.023 and 5.8(0.5;11.0)g/(m1.7*unit sleep score); p=0.031 respectively). Conclusions: Poor sleep quality is associated with higher LVMi in older African/African-Caribbeans and South Asians, but not in Europeans. This may contribute to cardiovascular risk. Keywords: sleep, left ventricle, hypertrophy, remodelling