Systematic Review of Self-Monitoring of Blood Glucose in Patients with Type 2 Diabetes

The benefit of self-monitoring of blood glucose (SMBG) in the reduction of HbA1c in non-insulin-treated participants remains unclear. HbA1c may be improved in this population with SMBG. We aimed to investigate this.
Meta-analyses of randomized controlled trials (RCTs) were performed comparing SMBG versus usual care and structured versus unstructured SMBG; the effect of clinician therapy adjustment based on SMBG readings was examined. Medline, Embase and Cochrane Central were electronically searched to identify articles published from 1 January 2000 to 30 June 2020. Trials investigating changes in HbA1c were selected. Screening was performed independently by two investigators. Two investigators extracted HbA1c at baseline and follow-up for each trial. Nineteen RCTs, involving 4,965 participants were included. Overall, SMBG reduced HbA1c. Preplanned subgroup analysis showed that using SMBG readings to adjust therapy contributed significantly to the reduction. No significant improvement in HbA1c was shown in SMBG without therapy adjustment). The same difference was observed in structured SMBG compared to unstructured SMBG.
HbA1c is improved with therapy adjustment based on structured SMBG readings. Implications are for clinicians to prescribe structured SMBG with an aim for therapy adjustment based on the readings, and not prescribing unstructured SMBG. Participants with suboptimal glycemic control may benefit most. A SMBG regimen that improves clinical- and cost-effectiveness is presented. Future studies can investigate this regimen specifically.