Periodontal inflammation and insulin resistance--lessons from obesity.

Recent attention has been focused on our understanding of the negative influences of oral chronic inflammation on systemic health. Successful periodontal treatment appears to have beneficial effects on the metabolic control of type 2 diabetes. Although type 2 diabetes is a multiple-risk-factor syndrome, lowered insulin sensitivity, called insulin resistance, is essential in developing the disease. Pro-inflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), produced from adipose tissues in obese subjects, is known to play a predominant role in inducing insulin resistance. Therefore, it can be hypothesized that anti-infectious periodontal treatment may improve metabolic control of diabetes via improved insulin sensitivity by reducing peripheral TNF-alpha concentration. In this review, we summarize the nature of insulin resistance and discuss the mechanisms by which insulin sensitivity is influenced by chronic inflammation, such as in periodontal disease.