The prevalence of obesity is increasing at an epidemic rate globally with more than 1 billion adults overweight and at least 300 million of them clinically obese. This is expected to rise further in the next 20 to 30 years. Obesity is known to be an independent risk factor for serious health conditions, including hypertension, type 2 diabetes, and cardiovascular diseases. Given the association of obesity with cardiovascular disease, it could be speculated that obese individuals would have adverse outcomes after a cardiovascular event compared to those with normal body mass index (BMI). However, various studies have reported a paradoxical U-shaped relationship between obesity and mortality from various diseases, including myocardial infarction and heart failure, suggesting that patients with higher BMI have similar or lower short- and long-term mortality rates. This phenomenon has been termed the 'obesity paradox' or 'reverse epidemiology'. The goal of this review is to evaluate the potential mechanisms behind the obesity paradox and its implications.
Keywords: Body mass index; coronary revascularization; myocardial infarction; obesity; obesity paradox; overweight; percutaneous coronary intervention; reverse epidemiology.
© The European Society of Cardiology 2014.