Men with beer bellies – even younger guys -- may be at increased risk for broken bones, a new study suggests.
It’s not just an issue of being obese, Harvard University researchers reported at this week's annual meeting of the Radiological Society of America in Chicago. It’s where the excess weight accumulates. Fat that is stored deep in the abdomen appears to be far more destructive than fat stashed just beneath the skin.
“We’ve known that this type of fat was a risk factor for diabetes and cardiovascular disease,” said the study’s lead researcher Dr. Miriam Bredella, an associate professor at the Harvard University Medical School and a radiologist at Boston’s Massachusetts General Hospital. “But now we know it’s a risk factor for bone loss.”
Bredella and her team studied 34 obese men whose average age was 34.
“These were young men who were obese, but otherwise completely healthy,” Bredella said. What they discovered was the men with large guts had much weaker bones, Bredella said.
Given the rising numbers of Americans who are entering the ranks of the obese, the report should give people pause. More than 78 million of us currently weigh in as obese, according to the Centers for Disease Control and Prevention. And while the rate among women seems to have plateaued, increasing numbers of men are moving into the obese category, according to a recent CDC report.
Because osteoporosis affects more women than men, it’s considered a women’s disease. The new study underscores the need for men to be aware that they, too, might be at risk for thinning bones.
The researchers first scanned the men’s abdomens and thighs to assess fat and muscle mass. Then the men underwent a high resolution CT scan of the forearm.
Half the men in the study had significant beer bellies, while the other half were just as obese, but their fat was distributed all over their bodies.
To get a sense of how strong the men’s bones were, Bredella and her colleagues used a computer technique known as finite element modeling.
“It works by breaking an object into tiny cubes and then predicting how each little cube will react if there is a force applied to it,” she explained. “The computer adds up all the elements and then can predict how strong the object is. The same kind of modeling is used in bridge and airplane design.
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“If you apply this modeling to bone, you can say exactly where the bone will break and how strong it is.”
The researchers don’t know yet how having abdominal fat hurts bone, but Bredella believes hormones play a role.
“Men and women who have a lot of [belly fat] have low growth hormone secretion,” she said. “And we know that growth hormone is very important for bone health. Vitamin D is another issue. Obese people sequester vitamin D into their fat cells. So even when they are getting normal levels of vitamin D, it’s trapped in the fat cells instead of circulating in the blood where it can get to the bone.”
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