Relationship Between BMI and Age at Diagnosis of Type 1 Diabetes in a Mediterranean Area in the Period of 1990–2004

In 2001, Wilkin (1) postulated that type 1 and type 2 diabetes are mostly the same disorder, only distinguished by the rate of β-cell loss with three different accelerators participating in the process (2,3).

Since 2002, many articles have supported the “accelerator hypothesis,” showing that BMI and changes in weight are inversely related to age at diagnosis of type 1 diabetes (4–6). Recently, Knerr et al. (7), in a large cohort of children with type 1 diabetes, concluded that a higher BMI was associated with a younger age at diagnosis of type 1 diabetes and that an increased weight gain could be considered a risk factor for early manifestation of the disease. Dabelea et al. (8) concluded that increasing BMI is associated with younger age at diagnosis only in subjects with a reduced β-cell function and hypothesized that obesity is accelerating the onset of type 1 diabetes at a higher stage in the natural history of the disease, after substantial autoimmune destruction of the β-cell has occurred. However, as expected, other studies did not agree with the postulate (9).

Until now, the data testing the accelerator hypothesis comes almost exclusively from Anglo-Saxon and central European populations. The aim of our study was to investigate the relationship between BMI and the age at onset of type 1 diabetes in a large cohort of Mediterranean subjects in whom diabetes became manifest between 1990 and 2004.