Self-monitoring of blood glucose in patients with type 2 diabetes who are not using insulin

Background: Self-monitoring of blood glucose (SMBG) has been found to be effective for patients with type 1 diabetes and for patients with type 2 diabetes using insulin. There is much debate on the effectiveness of SMBG as a tool in the self-management for patients with type 2 diabetes who are not using insulin.

Objectives: The objective of this review was to assess the effects of SMBG in patients with type 2 diabetes mellitus who are not using insulin.

Search strategy: Studies were obtained from searches of multiple electronic bibliographic databases supplemented with hand searches of references of retrieved articles. Date of last search: September 2004.

Selection criteria: We included randomised controlled trails investigating the effects of SMBG compared with usual care and/or with self-monitoring of urine glucose in patients with type 2 diabetes who where not using insulin. Included studies should have used at least one of the following outcome measures: glycaemic control, quality of life, well-being, patient satisfaction, or hypoglycaemic episodes.

Data collection and analysis: Two reviewers independently extracted data from included studies and assessed study quality. Data from the studies were compared to decide whether they were sufficiently homogeneous to pool in a meta-analysis.

Main results: Six randomised controlled trials were included in the review. Four trials compared SMBG with usual care, one trial compared SMBG with self-monitoring of urine glucose and there was one three-armed trial comparing SMBG with self-monitoring of urine glucose and usual care. Because of the differences in patient characteristics, interventions and outcomes between the studies, it was not possible to perform a meta-analysis. The methodological quality of studies was low. Two of the six studies reported a significant lowering effect of self-monitoring of blood glucose on HbA1c. However, one of these studies had a co-intervention with education on diet and lifestyle. There were few data on the effects of other outcomes and these effects were not statistically significant.

Authors' conclusions: From this review we concluded that self-monitoring of blood glucose might be effective in improving glycaemic control in patients with type 2 diabetes who are not using insulin. To assess the potential beneficial effects of SMBG in these patients a large and well-designed randomised controlled trial is required. This long-term trial should also investigate patient-related outcomes like quality of life, well-being and patient satisfaction, and provide adequate education to the patient to allow SMBG to be effective.