Effect of treatment of periodontitis on incretin axis in obese and non-obese individuals: A cohort study.

Context Periodontitis confers an increased risk of developing type 2 diabetes and, in patients with obesity, it might interfere with the incretin axis. The effect of periodontal treatment on glucoregulatory hormones remains unknown. Objective To evaluate the effect of periodontal treatment on incretin axis in obese and lean non-diabetic individuals. Setting King's College Dental Hospital and Institute, London, UK. Participants and methods The metabolic profile of obese and BMI-normal individuals affected by periodontitis was studied at baseline, 2 and 6 months after intensive periodontal treatment, by measuring plasma insulin, glucagon, GLP-1 and GIP and markers of systemic inflammation and oxidative stress. Main outcome measure(s) Circulating levels of incretins and inflammatory markers. Results At baseline, periodontal parameters were worse for obese than non-obese; this was accompanied by higher levels of circulating hs-CRP, insulin and GLP-1. The response to periodontal treatment was less favourable in the obese group, without significant variations of hs-CRP or malondialdehyde. Gluco-regulatory hormones changed differently after treatment: while insulin and glucagon did not vary at 2 and 6 months, GLP-1 and GIP significantly increased at 6 months in both groups. In particular, GLP-1 increased more rapidly in obese participants, while the increase of GIP followed similar trends across visits in both groups. Conclusions Nonsurgical treatment of periodontitis is associated with increased GLP-1 and GIP levels in non-obese and obese patients; changes in GLP-1 were more rapid in obese participants. This might have positive implications for the metabolic risk of these individuals.