High HbA1c at onset cannot be used as a predictor for future metabolic control for the individual child with type 1 diabetes mellitus

John Nilsson, Karin Åkesson, Lena Hanberger, Ulf Samuelsson

To study how metabolic control at onset of type 1 diabetes correlates to metabolic control and clinical parameters during childhood until transition from pediatric care to adult diabetes care. Data at onset, three months, one, three, and five years after diagnosis and at transition, on HbA1c and clinical parameters, on 8084 patients in the Swedish pediatric quality registry, SWEDIABKIDS, were used. Of these patients, 26% had been referred to adult diabetes care by 2014. Children with HbA1c < 72 mmol/mol (8.7%) (20% of patients, low group) at diagnosis continued to have good metabolic control during childhood, in contrast to children with HbA1c > 114 mmol/mol (12.6%) (20% of patients, high group) at diagnosis, who continued to have high HbA1c at follow-up. For the individual, there was no significant correlation between high HbA1c at onset and during follow-up. During follow-up, children in the high group were more often smokers, less physically active, and more often had retinopathy than children in the low group (P < .01, .01, .03 respectively). High HbA1c at onset was associated with high HbA1c during follow-up on a group level, but it cannot be used as a predictor of future metabolic control on an individual level. These results emphasize the important work done by the diabetes team in the first years after diagnosis. It is important to continuously set high goals for the achievement of tight metabolic control, in order to decrease the risk of microvascular complications.