Background and Aims Few studies are available on pulmonary function abnormalities in children with diabetes with controversial results. Spirometric abnormalities and reduction of lung diffusing capacity for carbon monoxide (DLCO) have been reported.

A cross sectional study was designed to assess whether children and adolescents with type 1 diabetes have pulmonary dysfunction.

Methods Spirometry measurements were performed and DLCO was measured. The final data analysis was conducted on 57 diabetics (mean age 14.4 + 3.09 years, 31 males) and 40 healthy controls (mean age 13.6 + 2.2 years, 19 males).

Results Although FVC, FEV1, FEV1/FVC of diabetics were lower than in control, significant statistical analysis was found only for FEF 25–75. Statistically significant differences between diabetic and control girls was noted with lower FEV1, lower FEV1/FVC, lower FEF25–75 and reduced DLCO/VA values in diabetic girls. Almost no correlation was found for diabetes duration, HbA1c, HRV indices and pulmonary function variables.

Conclusions In conclusion, the results of our study indicate subclinical lung impairment in children with T1DM, with significantly reduced FEF 25–75 compared to control subjects, indicating early small airway obstructive pattern. In this study, statistically significant differences between diabetic and control girls was noted, suggesting obstructive airway disease, according to the spirometric evaluation, but restrictive derangement indicated by reduced DLCO/VA. Since total lung capacity was not measured in our study, we can not talk about a restrictive pattern according to reduced DLCO/VA, but gender appeared a significant determinant for pulmonary dysfunction.