Endocrine Abstracts

Introduction: The incidence of Type 1 diabetes (T1D) is rising. The effect of increasing BMI in children has been proposed. A relationship between age of diagnosis of T1D and BMI SDS has been reported by some but not confirmed in all studies. We propose age of diagnosis and autoantibody status may be influenced by BMI and inherited factors relating to BMI and insulin resistance.

Methods: BMI SDS was calculated in 230 children with newly diagnosed T1D, 4–6 weeks post-diagnosis. Islet cell antibodies (ICA) were measured at diagnosis. Subjects were age and sex matched with a local control population (children with a history of urinary tract infection but normal DMSA imaging).

Maternal and paternal BMI and insulin sensitivity (Homa -IR) were measured (n=125) and compared with local age and sex matched controls. Ethical Committee approval was obtained for these studies.

Results: Children with newly diagnosed T1D were heavier than matched controls (Mean BMI SDS=0.66 versus 0.32; P=0.002). ICA+ve subjects were significantly heavier at diagnosis (Mean BMI SDS 0.88 n=90) than those who were ICA−ve (Mean BMI SDS =0.51 n=75 P=0.02). We found no relationship between age at diagnosis and BMI SDS in ICA+ve or ICA−ve subjects (r=0.082 and r=0.02). The parents of children with T1D were no heavier than controls. We found no difference in HOMA score between parents and controls and no relationship between parental HOMA score and age at diagnosis or ICA status in the child.

Conclusions: Increased adiposity at diagnosis of T1D may be associated with Autoantibody status but in contrast to smaller studies, BMI SDS had no influence on age of diagnosis in our cohort. We found no evidence of an inherited tendency to adiposity and no effect of inherited insulin sensitivity on age of diagnosis.