Increased incidence of type 1 diabetes in children and no change in the age of diagnosis and BMI-SDS at the onset - is the accelerator hypothesis not working?

Background: One of the speculated reasons for the observed increase of type 1 diabetes incidence in children is weight gain causing accelerated disease development in predisposed individuals. This so-called accelerator hypothesis is, however, controversial. The aim of the study was to analyze whether in the ethnically homogeneous population of Lesser Poland an increase in the number of cases of diabetes among children was associated with younger age and higher BMI-SDS at the moment of diagnosis. Subjects and Methods: Retrospective data analysis from medical records of all patients under the age of 14 (n=559; 50.6% male), with newly diagnosed type 1 diabetes in Lesser Poland between 1st of January 2006 and 31st of December 2017 (11 years). Results: The incidence ratio ranged significantly (P<0.001) from the lowest in 2006 (11.2/100,000/year) to the highest in 2012 (21.9/100,000/year). The mean age of diagnosis was 8.2+/-3.5 years; there was no trend of decreasing age (P=0.43). The mean body mass index expressed as the standard deviation score was -0.4+/-1.2. Almost all children (99%) at the time of diagnosis presented BMI-SDS within the normal range, with only 2.7% cases of obesity at the moment of diagnosis. Conclusion: The results of the present study do not confirm that increase of type 1 incidence in paediatric population is associated with younger age of diagnosis and higher BMI-SDS. Therefore are insufficient to prove the accelerator hypothesis.