Artículo de citocinas

J Periodontol • August 2008 (Suppl.)

The Role of Inflammatory Cytokines in Diabetes and Its Complications
George L. King*†
The prevalence of diabetes worldwide is increasing rapidly in association with the increase in obesity. Complications are a major fear of patients with diabetes. Complications of diabetes affect many tissues and organs, causing retinopathy, nephropathy, neuropathy,cardiovascular diseases, peripheral vascular diseases, stroke, and periodontal pathologies. Immunologic abnormalities are associated with type 1 and type 2 diabetes and diabetic complications. T cell abnormalities are believed to be the major cause of autoimmune disease in type 1 diabetes, leading to the destruction of pancreatic islets. In type 2 diabetes, inflammation and activation of monocytes arepostulated to be important for enhancing insulin resistance and may contribute to the loss of insulin secretory function by islet cells. Many factors can enhance insulin resistance, including genetics, a sedentary lifestyle, obesity, and other conditions, such as chronic inflammation or infection. Increases in inflammation, such as activation of monocytes and increased levels of inflammatory markers,e.g., C-reactive protein, plasminogen activator inhibitor-1, and other cytokines, were reported in insulin-resistant states without diabetes. One possible mechanism is that abnormal levels of metabolites, such as lipids, fatty acids, and various cytokines from the adipose tissue, activate monocytes and increase the secretion of inflammatory cytokines, enhancing insulin resistance. According to thismodel, obesity activates monocytes and enhances insulin resistance, increasing the risk for type 2 diabetes. Abnormalities in innate immunity might also participate in the development of diabetic complications. In general, hyperglycemia is the main initiator of diabetic retinopathy, nephropathy, and neuropathy, and it participates in the development of diabetic cardiovascular diseases. Althoughthe precise role of inflammation in the development of diabetic microvascular diseases is still unclear, it is likely that inflammation induced by diabetes and insulin resistance can accelerate atherosclerosis in patients with diabetes. Also, it was shown that conditions with an inflammatory basis, such as obesity and type 2 diabetes, can contribute to periodontal disease, suggesting that periodontalabnormalities may be partly influenced by inflammatory changes. Further research is required to confirm the role of inflammation and the onset of diabetes, microvascular diseases, and periodontal pathologies. J Periodontol 2008;79:1527-1534. KEY WORDS Complications; diabetes; hyperglycemia; inflammation; insulin resistance; periodontal disease.

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* Section on Vascular Cell Biology, Joslin DiabetesCenter, Boston, MA. † Department of Medicine, Harvard Medical School, Boston, MA.

iabetes is a growing concern. Its incidence is increasing rapidly and is predicted to increase further, in parallel with the trends observed for obesity.1-3 The increasing prevalence of diabetes represents a significant burden to human health because of its numerous and often serious complications. These includenephropathy, retinopathy, neuropathy, cardiovascular disease, and periodontitis.4 Diabetes also has an economic cost, with total direct and indirect medical costs already >$132 billion in the United States alone.5 Many factors are known to contribute to the development of diabetes and its complications. These include genetics, diet, sedentary lifestyle, perinatal factors, age, and obesity.6Nevertheless, an inflammatory basis for diabetes and its complications has been gaining interest. Inflammatory processes are associated with type 1 and type 2 diabetes; however, the distinct etiology of the two types of diabetes suggests that different causal mechanisms are involved. Type 1 diabetes is frequently found in childhood or young adulthood and arises from the autoimmune destruction of the...