Pulmonary function tests in type 1 diabetes adolescents with diabetic cardiovascular autonomic neuropathy

Chronic diabetic complications may afflict all organ tissues including cardiovascular and respiratory system. The aim of the study was to establish if the presence of cardiovascular autonomic neuropathy (CAN) was associated with impaired pulmonary function tests in adolescents with type 1 diabetes (T1D). 46 adolescents with T1D and 25 healthy subjects at the age 15-19years were enrolled to the study. Basic anthropometric data, diabetes onset and duration, plasma glucose and A1c were established. Pulmonary function tests were measured by spirometry and the presence of CAN was examined by heart rate variability. Adolescents with T1D had significantly lower pulmonary function test parameters - FVC (p<0.01), FEV1 (p<0.01), MMEF (p<0.05) and PEFR (p<0.05) compared to the control subjects. In diabetic group, patients with CAN (CAN+, n=19) had significantly lower FVC (p<0.05), FEV1 (p<0.05) and PEFR (p<0.05) compared to patients without CAN (CAN-, n=27). All spirometric parameters were significantly lower in CAN+ subjects compared to healthy controls; however, no significant difference was found in these parameters between CAN- subjects and healthy controls. Spirometric parameters (FVC, FEV1) significantly positively correlated with diabetes onset and body mass index; and negatively correlated with diabetes duration and resting heart rate. Our results indicate that CAN may be associated with reduced pulmonary functions in adolescents with T1D.