Impaired olfactory function is related to the presence of neuropathy in adults with type 1 diabetes

Olfactory dysfunction is suggested to be a clinical manifestation of central diabetic neuropathy. The aim of the study was to assess olfactory function in adult patients with type 1 diabetes.

A total of 106 patients with type 1 diabetes and 30 healthy subjects were included in the study. We evaluated the metabolic control of diabetes and the presence of chronic complications. Olfactory function was assessed with Sniffin' Sticks.

We found a negative correlation between olfactory identification scores and body mass index ( Rs -0.2; p = 0.04) and triglycerides ( Rs = -0.2; p = 0.04). We showed lower olfactory identification scores in neuropathy group versus non-neuropathy group [8 (interquartile range, 7-9) vs 10 (interquartile range, 9-11) points; p = 0.005]. In multivariate linear regression, impaired olfaction was independently associated with neuropathy (beta, -0.3; p = 0.005). In multivariate logistic regression, diabetes duration (odds ratio, 1.06; 95% confidence interval, 1.00-1.11; p = 0.04) and olfactory identification score (odds ratio, 0.61; 95% confidence interval, 0.43-0.85; p = 0.003) were independently associated with neuropathy.

Olfactory dysfunction is observed in patients with type 1 diabetes and diabetic peripheral neuropathy.