[Evaluation of respiratory function tests in children and adolescents with type 1 diabetes]

Changes in the respiratory system are little known, tardive complications of diabetes. The mechanisms which lead to dysfunctions of the respiratory system in patients with diabetes might be: microangiopathy of pulmonary vessels, changes of alveoli's structure, vegetative neuropathy of the respiratory system, changes of bronchi's reactivity and dysfunctions of the mobility of the thorax.

Evaluation of spirometry parameters in children and adolescents with type 1 diabetes mellitus and in the control group. Assessment of influence of metabolic control and duration of type 1 diabetes on chosen spirometric parameters among the patients from the study group.

Thirty five patients with type 1 diabetes mellitus and thirty eight healthy subjects underwent spirometry. Forced expiratory volume in the 1st second (FEV1), forced expiratory vital capacity (FVC EX), vital capacity (VC), peak expiratory flow (PEF), FEV1 to FVC EX ratio were compared with normal values and expressed as a percentage of normal in both groups. Kruskal-Wallis test and variant analysis were used to study differences in a few groups, while Mann-Whitney test or t-Student's test were used to study differences in two groups.

No statistical difference between vital capacity VC [%] in the study compared to the control group was found. In the study group, the FEV1 to FVC EX ratio was significantly higher than in the control group (p=0.00094). In the study group, peak expiratory flow PEF [%] was significantly lower than in the control group (p=0.01091). No statistical difference between FEV1 [%], FVC EX [%] in the study and control group was found. In the group of patients with HbA1c >7% vital capacity VC [%] was statistically lower (p=0.03729) compared to the control group. The FEV1 [%] values were in the normal range (>80% predicted values) for 34 patients. In one child from the study group the FEV1 [%] was under normal range. Values of FVC EX [%] were in the normal range (>80% predicted values) in 34 patients. Only in one child from the study group FVC EX [%] was under normal range. The FEV1 to FVC EX ratio was in the normal range (>70% predicted values) in 35 patients. The vital capacity value VC [%] was in the normal range (>80% predicted values) in 33 patients and in two of them VC [%] was under normal range.

No relation was found between the duration of type 1 diabetes, HbA1c percentage and chosen spirometric parameters among the patients from the study group. Poor metabolic control accounts for reduction of vital capacity among the diabetic patients.