Left-ventricular hypertrophy and obesity : a systematic review and meta-analysis of echocardiographic studies

AIM: Left-ventricular hypertrophy (LVH) is a frequent complication in obese individuals; an updated review and meta-analysis focusing on this issue is lacking. Thus, we analysed the literature in order to provide a comprehensive information on the left-ventricular structural changes, as assessed by echocardiography, associated to obesity. DESIGN: A literature search using the keywords 'left ventricle', 'left-ventricular hypertrophy', 'cardiac hypertrophy', 'obesity', 'hypertension' and 'echocardiography' was performed in order to identify relevant papers. Full articles published in English language in the past 12 years reporting studies in adult obese individuals were considered. RESULTS: A total of 22 studies including 5486 obese individuals were considered. Overall, in the pooled obese population, prevalence of LVH, defined by 12 criteria, was 56.0% (range 20.0-85.0%). Data provided by 15 studies (n=4999 obese individuals), including 6623 non-obese controls, showed that the probability of having LVH was much higher in cases than in non-obese counterparts (odds ratio 4.19, 95% confidence interval 2.67-6.53, P<0.01). A meta-regression analysis (n=2214; 14 studies) showed a direct correlation between BMI and left-ventricular mass (P<0.01). Among obese patients with LVH (n=1930; 15 studies), eccentric hypertrophy was more frequent than the concentric phenotype (66 versus 34%; P<0.01). CONCLUSIONS: Our analysis shows that LVH is present in a consistent fraction of the obese population and that eccentric hypertrophy prevails over the concentric phenotype. As obesity-related LVH is a powerful risk factor for systolic/diastolic dysfunction, the prevention/treatment of obesity may have a strong, favourable impact on incident heart failure.