The use of dipeptidyl-peptidase 4 (DPP-4) inhibitors and glucagon like peptide 1 (GLP1) analogues for the treatment of diabetic mellitus (DM) type 2 is growing (1,2). Currently, some of these agents have been approved in combination with insulin. The potential for combined use with insulin has garnered increasing attention due to reduce side effects associated with insulin therapy and improve glycemic control. Some investigators reported that GLP-1 analogue combined with insulin reduces HbA1c and weight with low risk of hypoglycemia and high treatment satisfaction (3). However, their duration of treatment was short time with less than a mean of 3.0 years and the alterations of chronic diabetic complications by combination with incretin-based and insulin therapies are not known.

We evaluated the long effects of adding incretin-based therapy (DPP-4 inhibitors or GLP-1 analogues) to insulin therapy on glycated hemoglobin (HbA1c) as glycemic control, body mass index (BMI), blood pressure (BP), insulin dosage, frequency of hypoglycemia, and chronic diabetic complications for 5 years-treatments.

Patients were treated with diet, exercise, and/or oral conventional pharmacotherapy combined with insulin. Oral conventional pharmacotherapy consisted of α-glycosidase inhibitors (α-GI), sulfonylurea (SU), biguanide (BG), thiazolidinedione (TZD), or combinations of these agents. Insulin therapy consisted of subcutaneous injections of long-acting insulin analogues prior to sleep and bolus subcutaneous injections of rapid-acting insulin analogues in multiple daily injections, or subcutaneous injections of mixed insulin analogues twice a day. In spite of the treatments, when the physician in charge judged that their values of HbA1c were inappropriate, the physician added the pharmacotherapy combined the insulin to incretin-based therapy. 2.3.2. For ethical reasons, patients were treated with various anti-hypertensive, anti-diabetic, anti-dyslipidemia and/or anti-hypercoagulation agents during the course of the study by the patients' own doctors as a part of continuing standard medical care. As to the drugs that have been used for the treatment of other disorders and its complication since the time before the study, the content should not be changed during the study in principle unless the complication is cured. If any new complication occurs during the study period, an appropriate treatment is given by the judgment of investigator.

Inclusion Criteria:

After a detailed baseline examination, 500 Japanese subjects with type 2 diabetes were followed up for all-cause mortality and morbidity. All participants visited our clinic regularly. All patients were fully informed about the purposes and procedures for the study and provided oral consent at enrolment.

Exclusion Criteria:

Patients participating in other clinical study. Other than the above, patients judged inappropriate as the subjects of this study by the investigator.