Obesity paradox - The controversial role of body mass index and plasma adiponectin in coronary artery disease and acute coronary syndrome

Body mass index (BMI) is an anthropometric index used to evaluate a person's weight. In the general population, higher BMI is associated with more adverse outcomes as well as cardiovascular risk factors. The current clinical guidelines suggest weight control within desirable BMI as 18.5 to 24.9 kg/m2. In the event of coronary artery disease or acute coronary syndrome, the impact of BMI on clinical outcomes still remains controversial. Some studies have demonstrated that overweight and obese patients had better prognosis than normal weight patients. Adiponectin, a secretory protein produced by adipocytes and inversely proportional to BMI, is a possiblemediator for the so-called "obesity paradox", a term for the obese-protective phenomenon. Lower plasma adiponectin is associated with the progression of coronary artery disease. However, in the presence of acute coronary syndrome, patients with higher plasma adiponectin could be associated with adverse outcomes. Further studies including serial change of plasma adiponectin, or the use of other methods to discriminate lean and fat body mass are necessary to investigate this seemingly contradictory topic.