A new study on a heart disease treatment reveals skinny, underweight patients are at the highest risk of death from any cause, including heart attacks.
While obesity and those overweight have long been cited as those with the greatest health risks for coronary issues, the latest study indicates that may not be true.
"At this stage we can only speculate on the reasons for this paradox," said lead study author Abhishek Sharma, M.D., from the Department of Medicine at Maimonides Medical Center in New York, in a press release.
"One explanation may be that overweight patients are more likely to be prescribed cardioprotective medications such as beta blockers and statins and in higher doses than the normal weight population. Further, obese and overweight patients have been found to have large coronary vessel damage, which might contribute to more favorable outcomes. This population may have a higher metabolic reserve, which might act protectively in chronic conditions like coronary artery disease," Sharma said.
The study included review of 36 studies regarding risks related to surgical procedures conducted to restore blood flow in coronary arteries, known as coronary revascularization procedures. The researchers separated patients by body weight or other estimates of body fat distribution. Each study reviewed had between 164 and 95,435 participants.
Patients in the underweight category were 2.59 times more likely to die from any cause following a revascularization procedure and those overweight, obese or severely obese had reduced risks of death due to any cause.
The study reveals overweight participants had a 28 percent reduced risk, the obese participants had a 27 percent reduced risk and the severely obese patients had a 22 percent reduced risk of dying due to any cause. The overweight participants had a 19 percent decreased risk of death due to heart disease compared with the normal weight participants.
Patients underweight were determined to be 1.79 times more likely than the normal weight participants to have a heart attack after undergoing revascularization.
The U.S. Centers for Disease Control and Prevention reports 69 percent of adults over the age of 20 are either overweight or obese.
One factor, said Sharma, regarding the findings is that overweight patients are more likely to be taking medication to protect heart health and that may play into the study results.
"Further," he said, "obese and overweight patients have been found to have large coronary vessel damage, which might contribute to more favorable outcomes. This population may have a higher metabolic reserve, which might act protectively in chronic conditions like CAD. Also, there could be a difference in the pathophysiology of cardiovascular disease in over- and underweight patients. A nonmodifiable genetic predisposition may also play a role in underweight patients."
The study review was published July 16 in Mayo Clinic Proceedings.