Impact of blood pressure and insulin on the relationship between body fat and left ventricular structure.

AIMS Obesity leads to hypertension and metabolic disturbances, as well as left ventricular hypertrophy and altered left ventricular geometry. However, the underlying mechanisms behind these relationships are not clear. The aim of this study was to investigate how body composition, blood pressure and metabolic factors relate to left ventricular mass and geometry. METHODS AND RESULTS We included 60 patients with obesity (BMI 31-52) and 43 non-obese subjects (BMI 18-27). Body weight, blood pressure and metabolic parameters were measured and echocardiography was performed. Body composition was determined by gender-specific anthropometric equations. Multivariate analyses showed that both body fat and lean body mass were independently and positively associated with left ventricular mass, whereas adipose tissue alone was related to relative wall thickness. When blood pressure was added to the model, the associations between body fat and left ventricular mass and geometry were weakened. Further adjustment for insulin levels eliminated the relationship between adipose tissue and relative wall thickness. CONCLUSIONS Both total adipose tissue and lean body mass predict an increase in myocardial mass, while adipose tissue alone is related to a rise in relative wall thickness. The concentric left ventricular geometry associated with body fat accumulation appears to be mediated, at least in part, by blood pressure and insulin levels.