Decreased jaw bone density and osteoblastic insulin signaling in a model of obesity

Previous studies have demonstrated that decreased bone mass results from either the impairment of osteoblastic insulin signaling or obesity. our previous study revealed that 12-week high-fat-diet (hfd) consumption caused obesity as well as peripheral and brain insulin resistance. however,the osteoblastic insulin resistance induced by hfd has not been elucidated. therefore,we hypothesized that 12-week hfd rats exhibited not only peripheral insulin resistance but also osteoblastic insulin resistance,which leads to decreased jawbone quality. we found that the jawbones of rats fed a 12-week hfd exhibited increased osteoporosis. the osteoblastic cells isolated from hfd-fed rats exhibited the impairment of osteoblastic insulin signaling as well as reduction of cell proliferation and survival. in conclusion,this study demonstrated that insulin resistance induced by 12-week hfd impaired osteoblastic insulin signaling,osteoblast proliferation,and osteoblast survival and resulted in osteoporosis in the jawbone. © international & american associations for dental research.