The purpose of this randomized, prospective trial is to determine wether (a) a once weekly glucose profile (self monitoring) or (b) a three-monthly report of the actual glycated haemoglobin are effective interventions to improve HbA1c after one year in typ 2-diabetic patients on conventional insulin treatment.

The design is an open, prospective, randomised, multicentre parallel group study. The total duration will be 5 years with patient recruitment over 4 years and an individual observation period of 1 year. 300 participants from 43 study centres, hospitals and private practices were recruited. The study will run for one year and aims to determine, whether there is an advantage with regard to HbA1c levels when (a) a regular three-monthly HbA1c or (b) a weekly 4-point glucose profile is taken and reported.

After screening, patients will be assigned at random to one of the following study arms:

1. no regular blood-glucose self-monitoring, no regular HbA1c
2. regular blood glucose self monitoring, no regular HbA1c
3. no regular blood glucose self monitoring, regular HbA1c
4. regular blood glucose self monitoring, regular HbA1c

The control for all participants is that urinary glucose should be monitored at least once a day, preferably in the late morning, as the highest increase in plasma glucose level occurs after breakfast.

Inclusion Criteria:

• Type 2-diabetes (ADA/WHO-Criteria)
• Conventional insulin therapy ( 1-3 daily injections of basal- and/or mixed insulin also in combination with oral agents.)
• Age:> 40 years
• BMI:> 20 kg/m²

Exclusion Criteria:

• Impaired liver function, defined as > 2 times upper limit of normal
• Impaired renal function defined liver enzymes as serum-creatinine > 1.3 mg/dl
• Gastro-intestinal diseases (disturbances, diagnoses)
• Inability to perform study-related activities according to the present protocol
• Pregnancy not certainly excluded
• Abuse of alcohol and/or other drugs
• Participation in other clinical trials during the past 3 month
• Threat to general state of health
• Intensified insulin therapy (at least 3 times rapid-acting insulin)
• Frequent blood glucose self monitoring during the past 3 months (more than one 4-point glucose profile per week or more than one blood glucose/ urinary glucose test per day )