Alcohol consumption and electrocardiographic left ventricular hypertrophy and mediation by elevated blood pressure in older Chinese men: the Guangzhou Biobank Cohort Study

BACKGROUND: Chinese people have a markedly lower alcohol consumption than people in the West. Whether alcohol consumption at such levels is associated with left ventricular hypertrophy, and the role of blood pressure (BP) in this relationship is unclear. We investigated the association between alcohol consumption and electrocardiographic left ventricular hypertrophy (ECG-LVH) and the mediating role of BP in Chinese men aged ≥50 years.

METHODS AND RESULTS: A case-control analysis was conducted on baseline cross-sectional data from the community-based Guangzhou Biobank Cohort Study (2003-2008), using standard 12-lead resting electrocardiograms. By comparing 191 new ECG-LVH cases with 4311 controls, excessive drinking (>210 g/week) showed excess risks for ECG-LVH (odds ratio [OR] = 1.90, 95% confidence interval [CI] = 1.12-3.24), after adjusting for education, income, occupation, physical activity, smoking, body mass index, fasting glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, BP, and antihypertensive medication. Mediation analysis showed a significant mediating effect of BP on the association between excessive drinking and ECG-LVH: systolic (31%) and diastolic (16%). After multivariate adjustment, no significant association was found between occasional drinking (<once/week: OR = 1.20, 95% CI = 0.80-1.80) and moderate drinking (≥once/week to ≤210 g/week: OR = 0.88, 95% CI = 0.53-1.47) with increased/decreased risk of ECG-LVH.

CONCLUSIONS: Alcohol consumption at >210 g/week in Chinese men is an independent risk factor for ECG-LVH. Low power prevented us from examining whether drinking at <once/week to ≤210 g/week is associated with decreased/increased risk of ECG-LVH. Elevated BP partially mediates between alcohol and ECG-LVH. A Mendelian randomization approach with a large sample size is warranted to determine the relations among alcohol consumption, BP, and LVH.