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