The findings of two new studies funded by the Juvenile Diabetes Research Foundation were announced on September 8, 2009, and published by the journal Diabetes Care. The first study showed that regular use of CGM is the principal factor in achieving better diabetes control. The second study showed that people using CGM to help manage their diabetes were able to sustain good diabetes control while actually lowering the incidence of hypoglycemia.
Research has shown that good blood sugar control is a key factor in reducing the risk of long-term complications. The JDRF study has now shown that, with CGM, hypoglycemia can be reduced while maintaining excellent blood sugar control over an extended period of time.
About the study
JDRF’s groundbreaking CGM Study was designed to clinically assess the benefits of CGM devices in helping people with type 1 diabetes manage their disease more effectively. It was a major multi-center trial, coordinated by the Jaeb Center for Health Research in Tampa, Florida and conducted at 10 medical centers across the United States, including the Lucile Packard Children’s Hospital at Stanford University. The study was an initial six month randomized and controlled trial involving 451 adults and children ranging in age from 8 to 72-years-old. Three age groups were analyzed separately: 8 to 14 years of age, 15 to 24 years of age, and 25 years of age or older. The initial study followed patients vigorously over a period of six month. A six month extension then tracked patients with less intensive follow-up than the first half, which was designed to approximate usual clinical practice.
The study design included A1C as a control, which measures long-term blood sugar management. Standards of good control are generally A1C below 7% for adults and below 7.5% to 8% for children, depending on age. Finding of an unrelated study had shown that a 10% improvement in A1C (7.2% vs. 8%) is associated with a 40% decrease in progression of eye disease.
Incidentally, on January 8, 2009, JDRF’s CGM Research was named one of Top 10 medical breakthroughs of 2008. http://www.jdrf.org/index.cfm?page_id=111318.
Study discoveries
As of today, September 30, 2009, JDRF has announced four discoveries all based on data analysis from the CGM Research.
The first study was announced by JDRF on September 8, 2008, at the European Association for the Study of Diabetes (EASD) annual meeting in Rome, and was published in the October 2, 2008, issue of the New England Journal of Medicine. The study found that improvements in blood sugar control were greatest for CGM patients 25 years of age or older, whose A1C levels decreased (improved) during the study by an average of 0.53% compared with control patients (p<0.001); improvements in secondary measurements were also significantly greater in CGM patients, including the percentage of patients able to achieve an A1C level below 7%, or a 10% relative or 0.5% absolute drop in A1C. The improvement in A1C occurred without an increase in hypoglycemia (low blood sugar), which is the worry when attempting to tighten glucose control. In children aged 8-14 years old, the average decrease in A1C was not significantly different in the CGM and control groups. Fifteen-to-24-year-old CGM patients, as a group did not experience significant improvements in glucose control compared with the control group. Although the study was not designed to assess the effect of frequency of CGM use on A1C, an analysis presented at EASD suggested that patients within all three age groups, including teens and young adults, who used the device at least six days a week had substantially lower A1Clevels after six months compared with patients who used CGM less than six days a week. http://www.jdrf.org/index.cfm?fuseaction=home.viewpage&page_id=33E55217-1321-C834-039BF1AA72DA90E4
The second study announced by JDRF was on May 27 2009, and published in Diabetes Care. The study had shown that CGM use had long-term impact: people who began the trial with A1C at 7% or above saw a reduction in A1C mainly in the first eight weeks of the study, and then remained relatively stable through the next 44 weeks; and participants who began the trials with an A1C below 7%, remained within that target range over the entire 12 months of the study. http://www.jdrf.org/index.cfm?page_id=111984
The third study announced by JDRF was on September 9, 2009, and were published online by Diabetes Care. The latest data show that the primary determinant of improvements in achieving better diabetes control is regular use of CGM- six days per week or more - rather than the age of patients, and that benefits continue well past the time when people with type 1 diabetes begin using the devices – including experiencing fewer low blood sugar emergencies. According to the Jaeb Center’s Dr. Roy W. Beck, the findings published in Diabetes Care, looking at those same trial results in a different way, show that after adjusting for the frequency of CGM use, the association of age group with improvements in A1C was no longer significant — in other words, participants in the trial in all age groups, from children through adults, who used CGM devices six days per week or more saw similar levels of improvement in their diabetes control. In addition, the study found that regular use of blood glucose testing prior to beginning CGM therapy was an excellent predictor of regular CGM use and thus of improvement in glucose control. http://www.jdrf.org/index.cfm?page_id=112539
The fourth announced study, was announced along with the third study and on the same date, and published in Diabetes Care. The study showed that CGM use had long-term impact: people who began the trial with A1C at 7% or above saw a reduction in A1C mainly in the first eight weeks of the study, and then remained relatively stable through the next 44 weeks; and participants who began the trials with an A1c below 7%, remained within that target range over the entire 12 months of the study. http://www.jdrf.org/index.cfm?page_id=112539
Discussion
“In this six-month extension to the trial, we found that most adults continued to use CGM almost every day, and had sustained benefits in diabetes control as measured by A1c levels and the amount of time blood sugar was in the target range,” said Dr. Aaron Kowalski, Program Director for Metabolic Control at JDRF. “These benefits persisted despite less intensive follow-up over the second half of the trial than the first, which was designed to approximate usual clinical practice.”
He noted that just as important as the persistence of control that CGM devices helped patients achieve was the remarkably low rate of severe hypoglycemic events during the second six months of the study. Severe hypoglycemic events — which required the assistance of another person or medical professional — were experienced by 10% of the study participants during the first six months of the trial, but only by 4% in the second six months. The rate of severe hypoglycemic events fell from 21.8 events per 100 person-years during the first six months to 7.1 events per 100 person-years during the second six months. The rate was not associated with the A1C level of the trial participants at the time the study began.
According to Dr. Tamborlane, an investigator in both the JDRF CGM Trial and the 1993 Diabetes Control and Complications Trial, the rate of severe hypoglycemia in people using CGM devices during the second six months of the JDRF trial was markedly lower than in the DCCT intensive treatment group, seven hypoglycemia events compared with 62 in the DCCT trial — even though the mean A1C of JDRF trial participants at 6.8% was lower than the DCCT trial participants’ level of 7.1%.
“Plus, the total absence of severe hypoglycemia during the second six months of the study in the participants who began the trial with an A1C below 7% is particularly striking, especially since these subjects were able to maintain a mean A1C of 6.4%,” Dr. Tamborlane said.
JDRF has actively shared the results of the CGM trial with health insurance plans, and as a result many of the nation’s leading plans including Aetna, Cigna, Kaiser Permanente, United Healthcare, and Wellpoint now cover CGM for patients with type 1 diabetes. In addition, due to the JDRF trial, CGM is now included in national standards of care for type 1 diabetes, making doctors more likely to prescribe them for patients.
More information on the JDRF CGM Trials, and on the Artificial Pancreas Project, is available online at http://www.artificialpancreas.org.
{ 1 trackback }