Subjective smell- and taste loss in diabetes-A questionnaire-based study on 47 011 individuals with diabetes and matched controls.

Background: Taste and smell disorders are more common in individuals with diabetes, particularly among those with low insulin sensitivity or central obesity. These disorders may affect glycaemic control by altering dietary habits. This study aimed to investigate self-reported taste and smell dysfunction in individuals with diabetes and explore associations with clinical and behavioural factors.

Methods: We examined self-reported taste and smell disorders in 47,011 individuals with or without diabetes using data from the Health in Central Denmark (HICD) cohort. In total, eight questions on subjective smell and taste function were included in the questionnaire.

Results: Participants with type 2 diabetes reported significantly more qualitative and quantitative chemosensory complaints than matched controls. In contrast, no significant differences were found between individuals with Type 1 Diabetes and controls. Smoking was consistently associated with increased complaints across all groups, while HbA1c levels showed no correlation with taste or smell disorders. Obesity, particularly in women with diabetes, was linked to higher symptom reporting CONCLUSIONS: Individuals with type 2 diabetes report more chemosensory complaints than controls. Smoking and obesity, but not HbA1c, were associated with a higher prevalence of symptoms. As subjective rating tends to underestimate true prevalence, future research should include objective testing to clarify how chemosensory disorders affect dietary behaviour and diabetes management.