Objective: Dysgeusia is a serious problem in patients with diabetes because it often leads to overeating, which is associated with disease progression. This study aimed to investigate the association between taste sensitivity, eating habits, and the oral environment.

Subjects and methods: In this cross-sectional study of 75 subjects with diabetes, gustatory function was assessed using the whole-mouth method, and lingual taste receptor gene expression was measured by real-time PCR. Food intake was evaluated using a food frequency questionnaire based on food groups. The oral environment was assessed using xerostomia and periodontal comprehensive examination.

Results: In total, 45.3%, 28.0%, and 18.7% of subjects showed lower umami taste sensitivity, low sweet taste sensitivity, and low salt taste sensitivity, respectively. Lower umami sensitivity correlated with lower estimated glomerular filtration rate and higher energy-source food intake. Subjects with diabetes with higher plaque control record showed significantly higher T1R3 gene expression than those with lower plaque control record.

Conclusion: Reduced umami taste sensitivity is associated with decreased renal function and high energy food intake in diabetes. Subjects with diabetes with higher plaque control record showed significantly higher T1R3 gene expression, suggesting that the oral environment affects taste gene expression. J. Med. Invest. 70 : 241-250, February, 2023.