Obesity is a risk factor for diabetes, high blood pressure, sleep apnea and other medical conditions that may contribute to heart problems. For a few years we have been baffled to see that studies show obese patients have higher survival after balloon angioplasty for coronary artery disease, hospitalization for heart failure and now something else. A recent study has now shown obese patients fair better after open heart surgery.
This is called the obesity paradox and it continues to surprise physicians and scientists. The obesity paradox has now emerged among coronary artery bypass graft (CABG) surgery patients in New Jersey. That is, an obese patient undergoing CABG in the state is significantly more likely to be alive several years later than is a normal-weight person.
Analysis of 60,635 patients in the state who underwent a CABG procedure during 1998-2007 showed a significantly greater mortality in normal-weight patients as compared with those who were overweight or obese, through 2 years of postsurgical follow-up.
This translated to a 29% reduction in the relative risk of death in overweight and a 30% decrease in mortality risk in obese patients.
Now, in an attempt to explain why obese patients fair better, we used to surmise that obese patients were younger when they required heart surgery and younger age was protective. In the current analysis though the authors adjusted for age, gender, smoking status, diabetes, and hypertension, and obesity was still protective. Counterintuitive right?
If obesity is a known risk factor for cardiovascular disease, how do we explain the obesity paradox?
It’s unclear to me.
- Dr O.
RELATED FROM AROUND THE WEB
On the one hand it is refreshing to hear a doctor say "We don't know!"
But on the other hand it is a bit scary to hear that.
I suspect that at some point some brilliant person will find the answer to this one. And then it will be on to the next paradox.