Blood glucose self-monitoring: No benefit for non-insulin-dependent patients with type 2 diabetes

Contrary to the widely-held belief, there is no proof that non-insulin-dependent patients with type 2 diabetes benefit from glucose self-monitoring. Moreover, it remains unclear whether an additional benefit is displayed by the blood test compared to the urine test or vice versa, in other words, whether one or other of the tests might offer an advantage to patients. The current data are quantitatively and qualitatively inadequate: the few trials that are suitable for investigating these questions have not included or have insufficiently reported many outcomes important to patients. Owing to their short duration, it is also not possible to draw any conclusions on the long-term benefit of glucose self-monitoring. This is the conclusion of the final report of the Institute for Quality and Efficiency in Health Care (IQWiG), published on 14 December 2009.

Self-monitoring is well established in insulin-dependent patients

Anyone who injects insulin should check their blood glucose level regularly, so that they can regulate the insulin dose according to need - this is an established procedure for patients with type 1 or type 2 diabetes. However, it is unclear whether people with type 2 diabetes, who manage without insulin, also benefit from blood glucose self-monitoring. The Federal Joint Committee (G-BA) therefore commissioned IQWiG to assess the patient-relevant benefit of urine glucose and blood glucose self-monitoring when treating diabetes type 2 without insulin.

Self-monitoring should also contribute towards changes in lifestyle

Besides drug therapy, lifestyle, especially diet and exercise, also plays an important role in the treatment of type 2 diabetes. Many experts assume that blood glucose self-monitoring helps patients in adapting their lifestyle, because the measured values enable them to see the direct effect of diet and physical activity and then to take suitable measures. The result should be that their blood glucose is better controlled and acute and long-term complications are reduced - at least this is the assumption.

Currently, there are two options for self-monitoring blood glucose. The kidneys excrete glucose via urine when the glucose level in the blood is too high. Patients can test for hyperglycaemia by carrying out a urine dipstick test. However, hypoglycaemia cannot be detected in this way. It can only be reliably detected by blood glucose monitoring: a small sample of blood is taken and placed on a test strip. In each case patients require thorough instruction in handling the test strips correctly and in being able to interpret the blood and urine test results and take appropriate action.

6 trials included in the assessment

In order to examine whether the above-mentioned assumptions can be scientifically proven, IQWiG searched for comparative trials with and without self-monitoring. Self-monitoring could also be a component of a complex education and treatment programme, such as are often offered to patients with diabetes mellitus. These trials were included if the participants in the treatment and control groups received the same treatment regimen - the only difference being that one group was with self-monitoring and the other without.