Immune-mediated disease and secondary failure to oral therapy in type 2 diabetes mellitus

Purpose: To determine the proportion of adults with type 2 diabetes, who developed secondary failure to oral medications that had immune-mediated diabetes (IMD). Subjects and methods: One hundred and eight subjects who failed to oral therapy were screened for autoantibodies (ICA, IAA, IA-2A, and GADA ₆₅) and HLA DR/DQ markers of IMD. Results: Mean age was 49 years and mean body mass index (BMI) was 31.5 kg/m²; 21.3% were non-Hispanic White (NHW), 32.3% Latin American (LA), and 43.2% African American (AA). Fourteen percent had one or more autoantibodies [Ab(+)]: five NHW, three LA, and seven AA. Ab(+) patients were younger (P=.03) and had lower body weight (P=.05) than Ab(-) patients. HLA markers of susceptibility for IMD were identified in 64% Ab(+) and in 43% Ab(-) (χ², P=.46). Conclusions: These results suggest that secondary failure to oral therapy can be due to continuing IMD in obese, type 2 diabetic individuals of varying ethnic backgrounds than those who have been traditionally associated with autoimmune type 1 diabetes. Screening for markers for IMD at diagnosis could be a useful way to predict those likely to develop secondary failure to oral therapy and may assist in the selection of medical therapy.