A.C. Felix Burden, MD
In patients with type 1 or type 2 diabetes mellitus, how do methods of insulin delivery and glucose monitoring compare for glycemic control?
Included studies compared methods of insulin delivery (multiple daily injections [MDIs] vs rapid-acting analogue-based continuous subcutaneous insulin infusion [CSII]) or methods of glucose monitoring (self-monitoring of blood glucose [SMBG] vs real-time continuous glucose monitoring [rt-CGM]) in children, adolescents, or adults with type 1 or type 2 diabetes. Studies that used regular insulin in a CSII group, or that included inpatients or patients who used a device for < 24 hours, were excluded. Outcomes included change in glycated hemoglobin (HbA1c) levels and severe hypoglycemia.
MEDLINE, EMBASE/Excerpta Medica, and Cochrane Central Register of Controlled Trials (all to Feb 2012); reference lists of included articles and relevant reviews; and clinicaltrials.gov were searched for randomized controlled trials (RCTs) that assessed process measures, intermediate outcomes, quality of life , or severe hypoglycemia; and for RCTs and observational studies that assessed microvascular or macrovascular outcomes, or mortality. Authors were contacted. After exclusion of 7 studies assessing children and adolescents exclusively, 26 trials (n = 3752) met inclusion criteria, with follow-up ranging from 12 weeks to 1 year. Study quality was poor in 1 RCT, fair in 11 trials, and good in 6; reviewers were not in agreement for 8 trials, which were assessed as poor-fair (5 RCTs), poor-good (1 RCT), and fair-good (2 RCTs). Trial size ranged from 12 to 966 patients.
The effects of insulin delivery and glucose-monitoring interventions on HbA1c are in the Table. In type 1 diabetes, neither CSII and MDIs (relative risk reduction [RRR] 28%, 95% CI −72 to 73)*, nor rt-CGM and SMBG (RRR 11%, CI −42 to 46)*, differed for severe hypoglycemia.
In patients with type 1 diabetes mellitus, real-time continuous glucose monitoring (rt-CGM) reduces glycated hemoglobin (HbA1c) more than self-monitoring of blood glucose (SMBG), and rt-CGM plus rapid-acting analogue-based continuous subcutaneous insulin infusion reduces HbA1c more than multiple daily injections plus SMBG. There is no evidence that these interventions differ for reducing severe hypoglycemia.
Insulin delivery or glucose-monitoring interventions for HbA1c in diabetes mellitus†
†CSII = rapid-acting analogue-based continuous subcutaneous insulin infusion; MDIs = multiple daily injections; rt-CGM = real-time continuous glucose monitoring; SMBG = self-monitoring of blood glucose; T1DM = type 1 diabetes mellitus; T2DM = type 2 diabetes mellitus; CI defined in Glossary.
‡Negative difference = greater reduction in the first intervention listed.
§I2 = 65%, P = 0.04. Sensitivity analysis excluding 1 trial in which baseline HbA1c levels were significantly higher than in the other studies: 3 trials (n = 91), mean between-group difference in change from baseline −0.01, 95% CI −35 to 34.
A.C. Felix Burden. Review: Continuous glucose monitoring reduces HbA1c more than self-monitoring in type 1 diabetes. Ann Intern Med. 2013;158:JC9. doi: 10.7326/0003-4819-158-6-201303190-02009
Download citation file:
Published: Ann Intern Med. 2013;158(6):JC9.
Cardiology, Coronary Risk Factors, Diabetes, Endocrine and Metabolism.
Results provided by:
Copyright © 2017 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use