Fitness and physical activity in youth with type 1 diabetes mellitus in good or poor glycemic control.

BackgroundPatients with type 1 diabetes mellitus (T1DM) may experience poor muscle health as a result of chronic hyperglycemia. Despite this, muscle function in children with T1DM with good or poor glycemic control has yet to be examined in detail. ObjectiveTo assess differences in muscle-related fitness variables in children with T1DM with good glycemic control (T1DM-G), as well as those with poor glycemic control (T1DM-P), and non-diabetic, healthy controls. SubjectsEight children with T1DM-G [glycosylated hemoglobin (HbA1c) 7.5% for 9 months], eight children with T1DM-P (HbA1c 9.0% for 9 months), and eight healthy controls completed one exercise session. MethodsAnaerobic and aerobic muscle functions were assessed with a maximal isometric grip strength test, a Wingate test, and an incremental continuous cycling test until exhaustion. Blood samples were collected at rest to determine HbA1c at the time of testing. Physical activity was monitored over 7 d using accelerometry. ResultsChildren with T1DM-P displayed lower peak oxygen consumption (VO2peak) values (mL/kg/min) compared to healthy controls (T1DM-P: 33.2 5.6, controls: 43.5 +/- 6.3, p < 0.01), while T1DM-G (43.5 +/- 6.3) had values similar to controls and T1DM-P. There was a negative relationship between VO2peak and HbA1c% (r = -0.54, p < 0.01). All groups were similar in all other fitness variables. There were no group differences in physical activity variables. Conclusion

Children with T1DM-G did not display signs of impaired muscle function, while children with T1DM-P have signs of altered aerobic muscle capacity.