Testing the Accelerator Hypothesis

Abstract

OBJECTIVE—Previous reports have predicted greater risk of type 1 diabetes among people who were heavier as young children. The Accelerator Hypothesis predicts earlier onset in heavier people, without necessarily a change in risk, and views type 1 and type 2 diabetes as the same disorder of insulin resistance, set against different genetic backgrounds. Insulin resistance is a function of fat mass, and increasing body weight in the industrialized world has been accompanied by earlier presentation (i.e., acceleration) of type 2 diabetes. We wanted to establish whether increasing body weight was also asociated with the earlier presentation of type 1 diabetes, as the Accelerator Hypothesis would predict. RESEARCH DESIGN AND METHODS— The relationships between fatness and age at diagnosis were examined in context of birth weight, weight change since birth, weight at diagnosis, BMI at diagnosis, and BMI 12 months later in 94 children aged 1–16 years (49 boys and 45 girls) presenting for management of acute-onset type 1 diabetes. RESULTS—BMI standard deviation score (SDS) at diagnosis, weight SDS change since birth, and BMI SDS 12 months later were all inversely related to age at presentation (r = −0.39 to −0.40, P < 0.001). The boys were significantly fatter than the girls (BMI SDS 0.56 vs. −0.08, respectively; P = 0.006) and presented with diabetes at a significantly younger age (6.74 vs. 8.32 years, respectively; P < 0.05). The sex difference in age at diagnosis, however, disappeared when corrected for BMI (P = 0.31), suggesting that fatness or something related to it was the responsible factor. CONCLUSIONS—The data are consistent with the hypothesis that the age at presentation of type 1 diabetes is associated with fatness. The implications for prevention of type 1 diabetes may be important.