Olfactory Performance of Children and Adolescents With Type 1 Diabetes: Relationship to Diabetes Duration and Glycemic Control.

BACKGROUND/OBJECTIVES: Olfactory dysfunction is increasingly recognized as a complication of diabetes that negatively impacts eating behavior and quality of life. This study investigates olfactory function in adolescents with Type 1 diabetes and evaluates the impact of disease duration and long-term glycemic control (mean HbA1c) on olfactory performance. METHODS: Olfactory function was assessed using the validated "Sniffin' Sticks" test, which evaluates odor threshold, discrimination, and identification to generate a composite TDI score for diagnosing hyposmia (TDI < 30.75). RESULTS: Hyposmia was identified in 30% of adolescents with Type 1 diabetes, whereas none exhibited anosmia. Overall olfactory performance (TDI scores) did not differ significantly by diabetes duration, age, sex, BMI, lipid profiles, or insulin therapy method. However, a strong negative correlation was observed between long-term mean HbA1c and total TDI scores (r = -0.65, p < 0.001). Logistic regression confirmed that elevated mean HbA1c (> 7.0%) was a significant independent predictor of olfactory impairment, increasing the risk of hyposmia 3.7-fold (OR = 3.726, p = 0.018). CONCLUSIONS: Poor long-term glycemic control significantly impairs olfactory function in adolescents with Type 1 diabetes. This is demonstrated by the marked reduction in olfactory scores among adolescents with high mean HbA1c. Consequently, future research may validate olfactory testing as an effective, early biomarker for diabetic complications.