NEW YORK — Continuous glucose monitoring has become the standard of care for managing patients with type 1 diabetes, based on results from three controlled trials, including two published last year.
Continuous glucose monitoring (CGM) has several advantages over self monitoring of blood glucose, Dr. Jay S. Skyler said at a meeting sponsored by the American Diabetes Association.
CGM provides real-time glucose information, and can provide an alarm if the patient becomes hypo- or hyperglycemic. It also gives patients and their physicians insight into glucose-level trends and into a patient's reaction to food and insulin. In addition, CGM is a tool for prompting behavior modification in patients with type 1 diabetes, said Dr. Skyler, a professor of medicine and director of the division of endocrinology, diabetes, and metabolism at the University of Miami.
“CGM is a useful tool because it improves outcomes and helps patients learn. I'm convinced that it is now the standard of care,” he said in an interview.
Dr. Skyler reported serving on the board of directors and being a shareholder in DexCom, which markets a continuous glucose monitor; he had similar relationships with MiniMed, another CGM device maker since was acquired by Medtronic. A third CGM device available in the United States is the Navigator unit marketed by Abbott.
The superiority of CGM to more conventional self monitoring of blood glucose was proven in three randomized studies.
The first assessed the HbA1c outcome in 156 patients who were randomized to continuous capillary blood glucose monitoring, biweekly capillary blood glucose monitoring for 3 days per week, or standard self monitoring. After 3 months, daily CGM led to an average reduction in HbA1c of 1.0%, compared with baseline, a significantly greater reduction than was seen in the control group. Intermittent CGM also led to a reduction in HbA1c, but the change was not significantly different from the control patients (Diabetes Care 2006;29:2730-2).
The second study randomized 138 patients to CGM or self monitoring. After 6 months, there was no significant difference in the extent of HbA1c reduction in the two treatment arms. But the patients on CGM had significantly fewer episodes of hypo- and hyperglycemia than did patients in the control group (Diabetes Technol. Ther. 2008;10:377-83).
The largest study so far reported randomized 322 adults and children with type 1 diabetes to management based on either CGM or SMBG. After 6 months, CGM led to a 0.5% cut in HbA1c compared with the control group in patients age 25 years or older, a statistically significant difference.
Among the patients aged 24 years or younger, no such difference developed between groups. This difference by age may have been due to more diligent use of the CGM devices and better use of the CGM information in self management by older patients, the researchers concluded (N. Engl. J. Med. 2008;359:1464-76).
CGM 'improves outcomes and helps patients learn. I'm convinced that it is now the standard of care.' DR. SKYLER