The purpose of the study is to clarify whether patients classified as Latent autoimmune diabetes of the adult (LADA) benefit from early treatment with insulin added to per oral treatment and lifestyle measures.

Latent autoimmune diabetes of the adult (LADA) is usually defined as a form of diabetes where the onset of diabetes takes place approximately after 30 years of age, where there is presence of beta-cell directed antibodies (mostly anti-GAD) and where there is no clinical need for insulin treatment during the first 6 months after the diagnosis of diabetes.

The aetiology and treatment of LADA patients is much less elucidated than is the case for type 1 diabetes (DM1) and type 2 diabetes (DM2). LADA constitutes about 10 % of the total diabetic population in many countries. LADA is therefore more common than insulin-requiring DM1.

LADA patients lose beta-cell function faster than patients with DM2. Residual beta-cell function in DM1 is coupled to better metabolic control with lesser degree of hyperglycemia, lesser frequency of hypoglycaemic events and lesser diabetic complications.

To retain beta-cell function in LADA patients is thus highly desirable.

There are several strategies to retain beta cell function. One therapeutic strategy is to induce some degree of "beta cell rest" by treatment with exogenous insulin. Several observations indicate that such a strategy can have beneficial effects.

This is a Scandinavian multicenter non-blinded clinical trial with 78 participants with newly diagnosed LADA. Participants will be randomized to either insulin- or per oral antidiabetic treatment. Participants will be followed up for 2 years after inclusion. Beta cell function and glycemic control will be monitored.

Inclusion Criteria:

• Diabetes diagnosed during 0-3 years before entering the study.
• Age > or equal to 30 years < or equal to 75 years
• anti-GAD positivity
• fasting C-peptide > or equal to 0,3 ng/ml
• no need for insulin treatment by clinical judgement for at least 3 months following the diagnosis of diabetes.
• HbA1c > 15 % above the upper limit of normal

Exclusion Criteria:

• Renal insufficiency (plasma creatinine > 150 mol/L)
• Severe retinopathy (proliferative or pre-proliferative)
• Severe cardiac disease (NYHA III-IV)
• Chronic severe illness judged by the investigator
• Females of reproductive age who wish to become pregnant during the study