INS and diabetes mellitus: This finding is probably related to the following factors: (1) the poorly controlled patients (high HbA1c groups) in the present study were relatively young; (2) the duration of diabetes in these patients was short; (3) the percentage of insulin users was low; (4) 33% of all patients were under diet therapy alone; and (5) the percentage of patients recently diagnosed with diabetes and with retained insulin secreting capability was high.