Dysgeusia is not only associated with zinc deficiency but also with certain drugs or diseases, including diabetes and renal failure. It often lowers the patient's quality of life and hinders access to proper nutrition. The underlying mechanism is unclear and there is a lack of awareness among patients. Here, we focused on lingual taste receptor gene expression in diabetes and elucidated the relationship between taste receptor gene expression and renal function. Forty-seven patients with diabetes and 10 healthy subjects (control group) were enrolled. Lingual foliate papillae were scraped and the derived cDNA was quantified by real-time polymerase chain reaction. Dysgeusia was assessed using SALSAVE?. All statistical analyses were performed using JMP? software 13. The expression of T1R1 and T1R2 was significantly upregulated in type 2 diabetes patients as compared with that in healthy subjects (P<0.01) but did not change in type 1 diabetes patients. T1R3 expression positively correlated and Scnn1 expression negatively correlated with estimated glomerular filtration rate, suggesting that altered taste receptor gene expression could reflect impaired renal function. Thus, alterations in T1R3 and Scnn1 expression in diabetes correlated with renal function. Taste receptor gene expression dysregulation could indicate dysgeusia associated with impaired renal function in patients with diabetes. J. Med. Invest. 69 : 120-126, February, 2022.