We tested the hypothesis that insulin therapy rather than sulfonylurea (SU) treatment has a preferable outcome to reverse or preserve beta cell function in the patients with diabetes that is called slowly progressive insulin-dependent (type 1) diabetes (SPIDDM) or latent autoimmune diabetes in adult (LADA).

In a multicenter, randomized, nonblinded clinical study, 4,089 non-insulin dependent diabetic patients were screened for glutamic acid decarboxylase autoantibodies (GADAb). Sixty GADAb-positive non-insulin requiring diabetic patients with duration of diabetes =/<5 years were assigned to either the SU group (n = 30) or the Insulin group (n = 30). Serum C-peptide response to annual oral glucose tolerance tests were followed for 57 mean months. The primary endpoint was insulin-dependency (IDDM: integrated C-peptide values [sigma C-peptide] <4 ng/ml).

Inclusion Criteria:

• Subjects should use SU agents to obtain as a goal good glycemic control.
• Duration of diabetes within 5 years from the onset (or diagnosis).

Exclusion Criteria:

• Subjects having history of hyperglycemia requiring insulin treatment and/or history of ketosis/ketoacidosis were excluded.
• Subjects with malignant diseases, systemic inflammatory diseases, renal or liver disorders or malabsorption were also excluded.