Higher risk of microvascular complications in smokers with type 1 diabetes despite intensive insulin therapy

• There is a strong relationship between smoking and microvascular complications.
• The risk of microvascular complications of diabetes is lower when you do not smoke.
• Intensive insulin therapy may decrease the risk for microvascular complications.
• Treatment with intensive insulin therapy is not sufficient especially when you smoke.

AimThe aim of the study was to evaluate the relationship between smoking status and the incidence of microvascular complications in patients with type 1 diabetes (DM1), treated with intensive functional insulin therapy (IFIT) from the onset of the disease.Methods81 participants (51 men, 30 women) of Poznan Prospective Study (PoProStu) with mean age of 34.0 ± 6.4 years were included in this analysis. Patients were observed for 10.0 ± 1.5 years. Evaluation of microvascular complications of diabetes, such as retinopathy, diabetic kidney disease and neuropathy was performed. Patients were divided into two groups depending on the smoking status: smokers and non-smokers.ResultsIn the group of smokers (n = 36) in comparison with patients who had never smoked (n = 45) any microangiopathy (58.3% vs 33.3%, p = 0.02), retinopathy (44.4% vs 20%, p = 0.02), diabetic kidney disease (47.2% vs 24.4%, p = 0.03) and neuropathy (25% vs 4.4%, p = 0.02) were found more often. A significant relationship, adjusted for age, sex, duration of diabetes, presence of hypertension and HbA1c between smoking and neuropathy and retinopathy was revealed [OR 10.16 (95%CI 1.59–64.95); p = 0.01 and OR 3.50 (95%CI 1.01–12.12); p = 0.04, respectively].ConclusionThe results show that in patients with DM1, there is a strong relationship between smoking and the diabetic microvascular complications, especially with neuropathy, despite treatment from the initial diagnosis with intensive insulin therapy.