Olfactory and gustatory functions in patients with non-complicated type 1 diabetes mellitus

The aim of this study was to evaluate any possible relationship between diabetic state and olfactory and gustatory functions in patients with non-complicated diabetes mellitus type 1 (T1D), and also to present evidence of the association between olfactory and gustatory scores and HbA1c values and disease durations. The study included 39 patients with non-complicated T1D and 31 healthy controls. Clinical characteristics such as age, gender, duration of disease, education levels and biochemical analyses (fasting blood glucose, urea, creatinine, total cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL-C), triglyceride, HbA1c, C-peptide, postprandial blood glucose) were measured. Subjective olfactory and gustatory tests were performed for all participants. There were no significant differences in olfactory tests between the two groups (odor thresholds 8.63 +/- 0.91 vs. 8.55 +/- 0.57, p = 0.66; odor discrimination 12.97 +/- 0.80 vs. 12.74 +/- 0.79, p = 0.24; odor identification 13.81 +/- 0.98 vs. 13.72 +/- 0.89, p = 0.69; TDI score 35.34 +/- 1.94 vs. 34.97 +/- 1.4, p = 0.37). There were also no significant differences in gustatory tests between the two groups (bitter 3.45 +/- 0.51 vs. 3.44 +/- 0.50, p = 0.90; sweet 3.32 +/- 0.48 vs. 3.38 +/- 0.49, p = 0.60; salty 3.13 +/- 0.72 vs. 3.10 +/- 0.72, p = 0.88; total score of taste 13.16 +/- 1.61 vs. 13.13 +/- 1.22, p = 0.92). Comparison of gustatory and olfactory scores according to disease duration of type 1 diabetes mellitus patients revealed that there were no differences between groups (all p > 0.05). T1D without complications may not be associated with olfactory and gustatory dysfunction according to subjective testing. We also found that gustatory and olfactory functions may not be related with HbA1c values and disease duration in non-complicated T1D.