EvidenceAlerts

Xu Y, Tan DHY, Lee JY Evaluating the impact of self-monitoring of blood glucose frequencies on glucose control in patients with type 2 diabetes who do not use insulin: A systematic review and meta-analysis. Int J Clin Pract. 2019 Jul;73(7):e13357. doi: 10.1111/ijcp.13357. Epub 2019 May 22. (Systematic review)
Abstract

AIMS: International diabetes guidelines have not established the frequencies of self-monitoring of blood glucose in patients with type 2 diabetes (T2D) who do not use insulin. The present study aimed to assess the impact of self-monitoring of blood glucose (SMBG) frequencies on the glucose control and other outcomes in non-insulin-treated patients with T2D.

METHODS: A literature search was performed in four databases. Randomised controlled trials with =6-month follow-up duration that compared the impact of different frequencies of SMBG on glycated haemoglobin A1c (HbA1c) were included. Studies with abstract only or reported effects of SMBG as a secondary outcome were excluded.

RESULTS: Of the 1557 studies identified, 12 RCTs with a total of 3350 patients were analysed. Overall, performing SMBG for 8 to 14 times per week was correlated with a better HbA1c control at 6 months (MD -0.46%, 95% CI -0.54 to -0.39) and 12 months (MD -0.20%, 95% CI -0.29 to -0.11). However, up to seven measurements of SMBG per week did not significantly affect glycaemic control. In addition, performing SMBG between 8 and 14 times per week was also associated with improved BMI (MD -0.46, 95% CI -0.84 to -0.08). When the results of SMBG were applied to adjust diabetes medication, a significant reduction in HbA1c levels was observed in the intervention arm compared to the control arm.

CONCLUSIONS: Eight to 14 measurements of SMBG per week were associated with an improved glycaemic control and a reduced BMI in patients with T2D not using insulin.

Ratings
Discipline Area Score
Family Medicine (FM)/General Practice (GP) 6 / 7
General Internal Medicine-Primary Care(US) 6 / 7
Internal Medicine 6 / 7
Endocrine 6 / 7
Comments from MORE raters

Endocrine rater

This superb study used randomized trials equalizing the education and compulsivity in the two frequency groups. The study shows once per day glucose monitoring is worthless. Patients need to know this and be told need to check bid if they really want better A1c control.

Internal Medicine rater

This reinforces the of SMBG.
Comments from EvidenceAlerts subscribers

Dr. Michael Allen (7/1/2019 11:55 PM)

This comment is based on reading just the abstract. My understanding is that the MCID for HbA1c is 0.5%, so these results show questionable benefit from more frequent SMBG.

Dr. Thomas Baitz (7/1/2019 9:09 PM)

If the frequency of SMBG was not prescribed by randomization but was a patient choice, then we must assume that more meticulous patients (i.e. more frequent SMBG) will and should have better diabetes control. If so, then the assumption that more frequent SMBG causes better control is invalid (cause and effect or common cause for correlated outcomes).