Objectives: The aim of this study was to investigate, in parallel, changes in electrogustometric (EGM) thresholds, the morphology and density of the fungiform papillae (fPap), and the shape and density of the vessels at the tip of the human tongue in patients with diabetes mellitus (DM).
Methodology: In 36 patients (19 females, 17 males; 12 subjects with type 1 DM and 24 subjects with type 2 DM), we recorded bilateral EGM-thresholds at the areas innervated by the chorda tympani, the glossopharyngeal nerves, and the greater petrosal nerves. We examined the morphology and density of the fPap and blood vessel density and morphology at the tip of the tongue with contact endoscopy (CE). A group of 36 healthy, age-matched, non-smoking individuals served as controls.
Results: The fPap density measured by CE was significantly (p < 0.05) reduced in DM compared to control groups. EGM-thresholds were significantly higher in the DM group than in the control group (p < 0.05). Gender did not have a significant impact on CE and EGM findings within the DM group. Body mass index did not significantly affect EGM-thresholds or the morphology and vascularization of fPap.
Conclusion: These results suggested that DM significantly reduced gustatory function, based on EGM, and impaired the gustatory anatomical structures, based on CE. Both EGM and CE may be useful in clinical settings to monitor taste disorders in patients with DM.