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.

INTRODUCTION Olfactory function is impaired in patients with type 1 diabetes and can be recognized as a form of diabetic neuropathy. Physical activity has various beneficial effects on type 1 diabetes. OBJECTIVES The aim of this study was to assess a relation between physical activity and olfactory function in patients with type 1 diabetes. PATIENTS AND METHODS We enrolled 120 patients with type 1 diabetes referred to an outpatient diabetes clinic. Patients with diabetes duration of less than 5 years, age above 65 years, concomitant diabetic ketoacidosis, and those using drugs affecting nasal mucosa were excluded. The final study sample included 90 patients. A control group comprised 22 healthy participants. Olfactory function was assessed using 12 odor‑emitting apens called Sniffin' Sticks. Physical activity was measured using the short version of the International Physical Activity Questionnaire (IPAQ‑SF). RESULTS There was a significant difference in the occurrence of hyposmia between diabetic patients and healthy controls (70.0% vs 45.5%, respectively; P = 0.03). There were no significant differences in IPAQ‑SF results between the groups. Moreover, IPAQ‑SF results correlated positively with olfactory test scores (r = 0.25; P = 0.02) and negatively with age. Additionally, patients with retinopathy and autonomic neuropathy obtained lower IPAQ‑SF scores than patients without those complications. A stepwise multivariable linear regression analysis indicated IPAQ scores, body mass index, and peripheral neuropathy as predictors of the olfactory test score (R = 0.2). CONCLUSIONS Our study confirms the beneficial role of physical activity in type 1 diabetes within the structures of the central nervous system.

The purpose of this study was to evaluate the impact of high intensity exercise on glucose levels and risk of metabolic decompensation in males with type 1 diabetes (T1D), depending on the method of insulin administration. The study comprised 29 males (aged 25.3±5.1 years; duration of diabetes 10.3±3.2 years) treated with continuous subcutaneous insulin infusion (CSII) or multiple daily insulin injections (MDI). Treadmill exercise test was performed twice in each patient until subjective exhaustion as maximum according to the Borg scale. All the patients achieved ≥85% of the maximal heart rate. Distance during the test was 4 500±1 400 m and 4 473±1 559 m in the MDI and CSII groups, respectively, which was achieved in 31±8 min. During the test and in the 6 h after, no clinically significant episodes of hypoglycemia occurred. Mean glucose levels did not exceed 10 mmol/L in most patients. The risk of the composite endpoint (hypoglycemia2.2 mmol/L) was higher in patients treated with MDI than CSII (OR3.75, 95%CI:1.22–11.52, p=0.02). In conclusion, planned high intensity physical effort in men with well-controlled T1D is metabolically safe. CSII shows greater metabolic advantage over MDI during and after high intensity exercise in men with T1D.