Clinical characteristics of insulin-dependent diabetes mellitus in children at diagnosis

Severity of clinical presentation in youth with type 1 diabetes is associated with differences in brain structure

OBJECTIVE

Differences in cognition and brain structure have been found in youth with type 1 diabetes compared with controls, even after relatively short disease duration. To determine whether severity of clinical presentation contributes to these differences, we obtained structural magnetic resonance imaging (MRI) scans in youth ages 7-17 who were either newly diagnosed with type 1 diabetes (<3.5 months from diagnosis, n  = 46) or a sibling without diabetes (n = 28).

RESEARCH DESIGN AND METHODS

Severity of presentation was measured by the presence of diabetic ketoacidosis (DKA) and degree of hyperglycemia exposure [hemoglobin A1c (HbA1c)] at diagnosis. MRI were obtained using T1-weighted, T2-weighted, and diffusion-weighted sequences.

RESULTS

Within the group with type 1 diabetes, 12 subjects presented in DKA and 34 did not. After controlling for age, sex, and multiple comparisons, the type 1 diabetes group had lower volume in the left temporal-parietal-occipital cortex compared with controls. Within the type 1 diabetes group, DKA at presentation was associated with lower radial, axial, and mean diffusivity (MD) throughout major white matter tracts and higher HbA1c was associated with lower hippocampal, thalamic, and cerebellar white matter volumes, lower right posterior parietal cortical thickness, and greater right occipital cortical thickness.

CONCLUSION

These data suggest that severity of clinical presentation is an important factor in predicting brain structural differences in youth with type 1 diabetes approximately 3 months after diagnosis.

The utility of hemoglobin A1c at diagnosis for prediction of future glycemic control in children with type 1 diabetes

INTRODUCTION

We evaluated the relationships of hemoglobin A1c (A1c) at diagnosis of type 1 diabetes (T1DM) to future glycemic control and to a series of clinical variables in children with T1DM.

MATERIALS AND METHODS

Patients <18 years old diagnosed with T1DM during a one year period who had an A1c at diagnosis and at least one follow-up visit at our center were eligible for inclusion. Baseline variables examined included age, race, gender, symptom duration, admission acuity, anthropometrics, bicarbonate, and A1c. Annual anthropometric and A1c data were also obtained from clinic visits through 4 years after diagnosis.

RESULTS

We identified 120 children (53 males). Mean age at diagnosis was 7.6±3.9 years. Mean A1c at diagnosis was 10.9±1.9%. A1c at diagnosis correlated with age at diagnosis, symptom duration, and A1c at 3-years, with trends towards correlations at 6 weeks and 4 years. A1c at 1 year correlated highly with A1c at subsequent visits. No other baseline variables correlated with subsequent glycemic control.

CONCLUSIONS

In children with newly diagnosed diabetes, A1cs at diagnosis and one year post diagnosis are related to subsequent glycemic control. Children with high A1cs particularly at one year post diagnosis may benefit from targeted intensification of resources.