control, relating median HbA1c-values in each patient during the prepubertal period with the respective values during
puberty, as well as in adulthood. The c2test was used to
analyze the relationship between tertiles of metabolic control
during prepuberty and adulthood, as well as the achievement
of adequate control as recommended in current guidelines.
To analyze the contribution of prepubertal metabolic control on adult HbA1c, a mixed hierarchic regression model
was used (dependent variable: HbA1c in adulthood, independent variable: HbA1c during prepuberty). Center was entered
as a random effect in the model (covariance structure: Cholesky), the intraclass correlation (between center variation)
was 21%. Estimation was based on residual pseudolikelihood, denominator degrees of freedom were calculated
according to Kenward-Roger, and iterations were optimized
according to Newton-Raphson. In addition to this simple
model, a fully adjusted model including sex, migration background, and year of manifestation, diabetes duration, insulin
therapy, and adult BMI together with type of treatment center was implemented.