Real-time continuous glucose monitoring lowered HbA1c with less risk for hypoglycemia
Using data from MEDLINE (1966 to February 2012), EMBASE (1974 to February 2012), and the Cochrane Central Register of Controlled Trials (1966 to February 2012), Hsin-Chieh Yeh, PhD, from the departments of medicine and epidemiology of the Johns Hopkins University, and colleagues conducted a systematic review of 33 randomized controlled trials (RCTs) in children or adults.
The studies compared continuous subcutaneous insulin infusion (CSII) with multiple daily injections (MDI) (n=19), real-time continuous glucose monitoring (rt-CGM) with self-monitoring of blood glucose (SMBG) (n=10), or sensor-augmented insulin pump with MDI and SMBG (n=4).
“Our review showed that CSII and MDI have similar effects on glycemic control and the incidence of severe hypoglycemia in children and adolescents with type 1 diabetes and in adults with type 2 diabetes,” researchers wrote.
In their meta-analysis, researchers examined seven studies comparing MDI with CSII in children and adolescents with type 1 diabetes. They said there was no difference between groups in HbA1c levels from baseline after 16 or more weeks of follow-up.
Results were found to be similar in adolescents aged 12 years or older (combined mean between-arm difference in change from baseline in HbA1c=–0.10% [95% CI, –0.48 to 0.27%]). However, these findings were less exact among children aged 12 years and younger (combined mean between-arm difference in change from baseline in HbA1c=–0.05% [95% CI, –1.01 to 0.96%]), they wrote.
Additionally, eight studies compared MDI with CSII in adults with type 1 diabetes, and four studies compared MDI with CSII in adults with type 2 diabetes. The evidence in both adult type 1 and type 2 diabetes patients was not sufficient enough to make conclusions about the effects of CSII versus MDI on nocturnal hypoglycemia, hyperglycemia, or quality of life (QOL), the researchers wrote.
Further data demonstrate that patients treated with rt-CGM achieved a lower HbA1c compared with SMBG (between-arm difference of change=–0.26% [95% CI, –0.33% to –0.19%]), without any difference in severe hypoglycemia.
Sensor-augmented pump use reduced HbA1c more than MDI and SMBG in type 1 diabetes (between-arm difference of change=–0.68% [95% CI, –0.81 to –0.54]). Yeh and colleagues said little evidence was available on other outcomes.
“Our findings indicate that rt-CGM is superior to SMBG in lowering HbA1c levels, without increasing the risk of severe hypoglycemia, in type 1 diabetes, particularly those who are compliant with using the monitoring device,” researchers concluded.
Despite these findings, Yeh and colleagues said that future research should include larger studies in populations where diabetes is growing; specifically elderly patients, patients with type 2 diabetes on insulin therapy, and minority populations.
Disclosure: Drs. Yeh, Bass, Berger, Wilson, Haberl, Golden, and Ranasinghe report receiving institution grant money from Agency for Healthcare Research and Quality (AHRQ). Dr. Maruthur is an employee of Johns Hopkins University and reports money paid to him from AHRQ, federal grants from several entities, and consultancy fees from Doctor Evidence. Dr. Berg reports receiving grant and consultancy fee or honorarium from Roche, as well as board membership and speaker’s bureaus money paid to him from Roche, MSD Pharmaceuticals, Gilead Sciences Inc., Janssen Pharmaceuticals, Tibotec Pharmaceuticals, Bristol-Myers Squibb, Abbott Laboratories and Novartis. Dr. Suh reports no relevant financial disclosures.