β-cell autoimmunity in overweight non-diabetic youth: any implications?

The presence of β-cell antibodies is associated with a high risk of type 1 diabetes. With increasing rates of obesity, the distinction between obese T1DM and T2DM has become difficult. Moreover, increasing body mass index (BMI) in at-risk children has been proposed not only as a possible contributor to T1DM by increasing insulin resistance, but also as exerting an effect via the immunomodulatory properties of certain adipokines. This study aimed to determine prevalence of β-cell autoantibodies (AA) in overweight non-diabetic children and assess insulin sensitivity and secretion derived from an oral glucose tolerance test (OGTT) in those with vs. without ß-cell AA.

A total of 357 overweight (BMI > 85%) youths underwent OGTTs, dual energy X-ray absorptiometry (DEXA) and measurement of GAD65 and IA-2 AA according to the NIDDK harmonization assay. Using the same methodology, AA were measured in 90 normal weight, non-diabetic individuals.

About 1.9% of overweight and 4.4% of control normal weight children had evidence of β-cell autoimmunity, with GAD65 AA detected in all subjects but none with IA-2. Youth with positive vs. those with negative AA had higher leptin/adiponectin ratio, glucose at 60 min and C-peptide at 90 min.

These findings suggest that the prevalence of β-cell AA in overweight youth may be similar to that in non-overweight children. Further studies using standardized methods are required.