Obesity and target organ damage: the heart

In most patients, coronary atherosclerosis or congestive heart failure develop as an integrated response to multiple cardiovascular risk factors. Obesity increases the prevalence of most cardiovascular risk factors and is the predominant cause of diabetes mellitus and arterial hypertension. Moreover, obesity shifts the manifestation of these risk factors to younger age groups, such that subsequent damage results prematurely in clinically overt cardiac diseases. In addition, due to clustering of obesity-related risk factors, obesity may amplify the risk by synergistic mechanisms acting in parallel. Finally, an elevated body mass index (BMI) results in an increase in heart rate and blood volume, as well as increased systolic and diastolic blood pressure. These changes affect cardiac geometry and mass in addition to the alterations of the coronary vasculature. At the population level, the role of obesity in promoting multiple risk factors and, subsequently, the development of heart diseases cannot be underestimated. In individual patients, however, the clinical presentation may be dominated by obesity-related hypertension, diabetes, metabolic and inflammatory derangements or clinical symptoms of heart failure or coronary artery disease. Weight reduction remains a crucial component of the therapeutic strategy to ameliorate insulin resistance, hypertension and left ventricular hypertrophy, among other risk factors, with profound implications for the individual's prognosis.