When we corrected for the amount of muscle, we found that the obese person is not making as much bone as they should be for the amount of muscle that they have, Pollock said. People havent observed that in the past because they werent using the three-dimensional scan.
Lewis said the exact mechanisms by which excess fat hinders bone strength are unclear, but studies of obese rats show that they produce more fat cells in the bone marrow and fewer bone cells. Since fat and bone cells originate from the same precursor, it may be that fat cell production is favored over bone cell production in obese people.
The women the researchers studied were 18 and 19, an age at which the bones have stopped growing but before age-related degeneration begins. Lewis said future studies using three-dimensional bone imaging should follow children with normal and high levels of body fat through time to see how their skeletons grow. Other researchers have documented increased fractures in overweight children, suggesting that childhood obesity may be particularly detrimental to bone health.
When youre young you have the capacity to change the shape of your bones, but when you get older you dont have that capacity. Lewis said. And because of that, childhood obesity could have a significant, long lasting negative impact on the skeleton.
|Contact: Sam Fahmy|
University of Georgia