We read with great interest the well-written and well-done study from Israel by Benderly et al from the Bezafibrate Infarction Prevention (BIP) database examining the relation of body mass index (BMI) to mortality in men with coronary heart disease (CHD). Importantly, in their study, they demonstrated a U-shaped association, with the highest risk in the lean (BMI <20 kg/m 2 ) and in the obese (BMI ≥30 kg/m 2 ) groups. It is critical to point out that these results are different from those of many other studies and meta-analyses, in which overweight (BMI 25 to 30 kg/m 2 ) and obese (or at least mildly obese; BMI 30 to 35 kg/m 2 ) patients have lower mortality than “normal”-BMI patients.
The investigators state that their results in 12,466 men with CHD were “in line with a recent meta-analysis of data from 388,622 patients in 26 observation studies.” However, these data were from epidemiologic studies, not cohorts with known CHD. We recently reported on 529 patients with CHD, and even moderately obese patients (BMI >35 kg/m 2 ) had lower mortality than lean patients. 4 More important, Romero-Corral et al 5 performed a meta-analysis of 40 studies of 250,000 patients with CHD with mean follow-up of 3.8 years and found that overweight and mildly obese (BMI 30 to 35 kg/m 2 ) patients had lower mortality than “normal”-BMI patients with CHD. However, they did demonstrate that patients with CHD with moderate obesity (BMI >35 kg/m 2 ) had increased mortality. This is important to note, because data across most of the Western world demonstrate that mortality continues to be low in patients with CHD with overweight and mild obesity, which is different from the results in this study from a unique population from Israel.
Clearly, obesity and its complications (hypertension, dyslipidemia, metabolic syndrome, type 2 diabetes mellitus, left ventricular hypertrophy, etc.) markedly increase the risk for developing many cardiovascular diseases, including CHD and heart failure. However, in patients with established cardiac diseases, including hypertension, CHD, heart failure, atrial fibrillation, and peripheral arterial disease, and even patients referred for stress testing and echocardiography, numerous studies and meta-analyses have demonstrated an “obesity paradox,” whereby overweight and obese patients have better prognoses than leaner patients with similar heart disease. Besides demonstrating this paradox with BMI, we have also demonstrated the same paradox with body fat, whereby patients with CHD as well as those with advanced heart failure with higher body fat had better prognoses than patients with low body fat.
We believe that efforts to prevent overweight and obesity will likely lead to reductions in cardiovascular diseases in the first place. 2 Also, as Benderly et al 1 review, in patients with advanced heart disease and despite the “obesity paradox,” the constellation of data currently support efforts at purposeful weight reduction.