Washington: Overweight adolescents may develop weak bones, besides facing a host of health problems.
A study of 143 overweight 14-18-year olds shows those with risk factors such as low levels of HDL (high-density lipoprotein) cholesterol (good cholesterol) have less bone mass, an indicator of bone strength than their overweight but otherwise healthy peers.
Other risk factors included high fat levels in the blood, higher blood pressure (BP) and a larger waist size, said Norman Pollock, study co-author and bone biologist at Georgia Health Sciences University, The Journal of Paediatrics reports.
In fact, total body fat didn`t seem to impact bone mass. It was fat around the middle that seemed to increase the risk for bad bones just like it does the risk of diabetes and heart disease, according to a Georgia University statement.
"The more risk factors you have, the less bone mass you have," Pollock said, noting that 62 percent of the overweight adolescents had at least one risk factor. It also indicates that the concept of "fit and fat" may apply to the bones.
Participants without one or more of these risk factors tended to get slightly more vigorous physical activity although none of the participants got the recommended 60-plus minutes of daily physical activity, Pollock said.
Vigorous activity is defined as the activity that increases the heart rate high enough to cause heavy breathing, such as jogging, tennis or jumping jacks.
Physical activity is known to prompt bones to release a hormone called osteocalcin, which helps decrease fat-related risk factors such as insulin resistance.
"We are now beginning to respect the bones as an endocrine organ like we do now with fat and muscle," Pollock noted. Activity also increases the number of bone-producing cells called osteoblasts.
The study appears to be the first analyzing bone-fat relationships and cardiometabolic risk factors in youth.