Evaluation of Taste Perception and Olfactory Function in Adolescents in Relation to the Duration of Type 1 Diabetes

Background: Olfactory dysfunction may be one of the clinical symptoms of neuropathy in diabetics. It is also known that taste and smell disorders in diabetes may impact dietary adherence and, consequently, good glycemic control. The study aimed to investigate taste perception and olfactory function in adolescents with type 1 diabetes (T1D) compared to the control group. Materials and Methods: The study was conducted on patients aged 11-15 from south-eastern Poland with T1D in the diabetes clinic of the 2nd Department of Pediatrics, Endocrinology, and Diabetology of the Provincial Clinical Hospital No. 2 in Rzeszów. Taste strips (sweet, salty, sour, and bitter), U-Sniff sticks (12 selected smells), and a filter paper strip impregnated with n-propylthiouracil (PROP) were used. Results: No significant differences were observed between both the groups in the taste tests, except for the sweet taste test. The sweet taste test scores were higher for diabetes, for whom the median score was 4 (3.0-4.0), than for the control group, for whom the median score was 3.0 (3.0-4.0), (p=0.0001). These results mean that diabetics were more sensitive to sweet taste. We also found no significant differences between T1D and the control group of the U-Sniff test. However, significantly lower U-Sniff test scores were seen in adolescents with diabetes of more than 10 years. Median U-Sniff test scores for people with diabetes for 10 years were 11 (10.0-12.0) while in the control group median was 10.0 (9.0-12.0), (p=0.0370). The analysis also showed that adolescents suffering from long-term T1D more often incorrectly identified bitter tastes than healthy adolescents. Conclusion: The duration of diabetes is important regarding changes in taste perception and olfactory function in adolescents with diabetes.