Evaluation of gustatory function in patients with diabetes mellitus type 2

Objectives. The aim of this study was to evaluate the gustatory function of patients with diabetes mellitus type 2 and to compare gustatory appreciation on right and left sides of the tongue and soft palate. Study design. The study group was composed of 40 controlled and 40 uncontrolled diabetes mellitus type 2 patients. A group of 40 age-and gender-matched healthy control subjects were also evaluated. Gustatory function was tested by administering a whole-mouth above-threshold test and spatial taste test using sucrose, sodium chloride (NaCl), citric acid, and quinine hydrochloride solutions. Statistical analysis was performed using 1-way ANOVA and Student t test. Results. Taste impairment was found in the controlled and uncontrolled diabetic patients relative to healthy control subjects (P < .0001). A highly significant difference was noticed for sweet (P = .00001) and sour (P = .00002) tastes. For salt taste, a significant difference was found (P = .001). Hypogeusia was reported among 50 (62.5%) of the diabetic patients versus 5 (12.5%) of control subjects (P < .0001). Ageusia to sweet was found in 6 uncontrolled diabetic patients (P < .0001). For almost all 120 subjects, taste sensitivity was found to be equivalent on left and right sides of the tongue and soft palate. Conclusion. Type 2 diabetic patients had a blunted taste response for sweet followed by sour and salt tastes. This taste abnormality may influence the choice of nutrients, with a preference for sweet-tasting foods, thereby exacerbating hyperglycemia. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: 876-880)