Overweight, prepubertal children with prediabetes at increased risk for low BMD

Pollock NK. J Bone Miner Res. 2010;doi:10.1002/jbmr.184.

Children who are overweight are not only at an increased risk for diabetes before puberty, but new findings suggest that they are also at an increased risk for low bone mineral density. Central adiposity may be more likely to decrease bone development when compared with overall adiposity in this population.

“This finding provides the first clue linking childhood obesity to skeletal fractures,” Norman K. Pollock, MD, of the department of pediatrics at Georgia Prevention Institute, Medical College of Georgia, said in a press release. “While overweight children may have more bone mass than normal-weight kids, it may not be big or strong enough to compensate for their larger size.”

Pollock and colleagues compared BMD between overweight children aged between 7 and 11 years with (n=41) and without (n=99) prediabetes (43% girls; 46% black). The associations between BMD and total and central adiposity, glucose intolerance, insulin sensitivity, lipid profile, systemic inflammation and osteocalcin were also measured.

After controlling for gender, ethnicity, weight and height, children with prediabetes had a 4% lower total BMD when compared with children without prediabetes (P=.03).

Although overall adiposity was positively associated with BMD (P=.01), both visceral adipose tissue (P=.03) and subcutaneous abdominal adipose tissue (P=.02) were inversely associated with BMD.

Pollock said this association may more likely be caused by the way adiposity is distributed throughout the body. Those with prediabetes are more likely to have central adiposity, which is associated with diabetes and cardiovascular disease.

“Taken together, it seems that excessive abdominal fat may play a key role linking prediabetes to lower bone mass,” Pollock said. “Our greatest window of opportunity to enhance bone strength and ultimately reduce the risk of osteoporosis is during childhood, before the capacity to build bone diminishes. One of the best things you can do for bone development and general health is exercise.”

Future research will include determining how central adiposity impairs BMD.