[ACEsthetics] endo lesions mess with insulin sensitivity

A rat study shows endo lesions mess with insulin sensitivity.

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regards

bill domb

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http://www.sciencedirect.com/science/article/pii/S0099239913000216

Periapical Lesions Decrease Insulin Signal and Cause Insulin Resistance

• Rafael Dias Astolphi, MSc^∗,
• Mariane Machado Curbete, MSc^∗,
• Natalia Helena Colombo, MSc^∗,
• Daisy Jaqueline Shirakashi, MSc^∗,
• Fernando Yamamoto Chiba, PhD^†,
• Annelise Katrine Carrara Prieto, MSc^‡,
• Luciano Tavares Angelo Cintra, PhD^‡,
• Suely Regina Mogami Bomfim, PhD^§,
• Edilson Ervolino, PhD^∗,
• Doris Hissako Sumida, PhD^{∗, ,}

• ^∗ Basic Sciences, Araçatuba Dental School, UNESP–Universidade Estadual Paulista, Araçatuba, Sao Paulo, Brazil
• ^† Child and Social Dentistry, Araçatuba Dental School, UNESP–Universidade Estadual Paulista, Araçatuba, Sao Paulo, Brazil
• ^‡ Endodontics, Araçatuba Dental School, UNESP–Universidade Estadual Paulista, Araçatuba, Sao Paulo, Brazil
• ^§ Clinic and Surgery and Animal Reproduction, Araçatuba Veterinary Medicine School, UNESP–Universidade Estadual Paulista, Araçatuba, SP, Brazil

• http://dx.doi.org/10.1016/j.joen.2012.12.031, How to Cite or Link Using DOI

Introduction

Inflammatory cytokines are associated with decreased insulin signal transduction. Moreover, local oral inflammation, such as that accompanying periodontal disease, is associated with insulin resistance and type 2 diabetes mellitus. The aim of this study was to evaluate the effect of periapical lesions (PLs) on insulin signaling and insulin sensitivity in rats. We hypothesized that PLs alter systemic insulin signaling and insulin sensitivity via elevated plasmatic tumor necrosis factor α (TNF-α).

Methods

Wistar rats were divided into control (CN) and PL groups. PLs were induced by exposing pulpal tissue to the oral environment. After 30 days, insulin sensitivity was measured using the insulin tolerance test. After euthanization, maxillae were processed for histopathology. Plasmatic concentrations of tumor necrosis factor α (TNF-α) were determined via the enzyme-linked immunosorbent assay. Insulin signal transduction was evaluated using insulin receptor substrate tyrosine phosphorylation status and serine phosphorylation status in periepididymal white adipose tissue via Western blotting. For insulin signaling and insulin tolerance tests, the analyses performed were analysis of variance followed by the Tukey post hoc test. For TNF-α analysis, the Student's t test was used. In all tests, P < .05 was considered significant.

Results

The rats with PLs showed higher plasmatic TNF-α, lower constant rate for glucose disappearance values, and reduced pp185 tyrosine phosphorylation status but no change in serine phosphorylation status in white adipose tissue after insulin stimulation.

Conclusions

PLs can cause alterations to both insulin signaling and insulin sensitivity, probably because of elevation of plasmatic TNF-α. The results from this study emphasize the importance of the prevention of local inflammatory diseases, such as PLs, with regard to the prevention of insulin resistance.