ORLANDO -- Use of continuous glucose monitors didn't make much difference in achieving tight glucose control for hospitalized type 2 diabetes patients, the TIGHT trial showed.
Patients randomized to an intensive control target of 90-130 mg/dL ended up with a similar mean glucose compared with those assigned a standard 140-180 mg/dL treatment target (170 vs 175 mg/dL, P=0.25), Guillermo Umpierrez, MD, of Emory University in Atlanta, reported at the American Diabetes Association (ADA) annual meeting.
Reassuringly, CGM-measured hypoglycemia was uncommon with either the tight or standard treatment target (0.2% vs 0.4% of the time under 54 mg/dL).
As to why neither group did very well at control despite the CGM, co-presenter Irl B. Hirsch, MD, of the University of Washington in Seattle, pointed to nursing issues, prandial dosing problems, and the overall difficulty of managing these patients.
The study demonstrated that reaching guideline-recommended treatment targets is extremely difficult in a typical type 2 diabetes population, even with CGM and even in academic centers of excellence, he concluded at the session. "CGM could be helpful, but it will require other changes with training, insulin protocols/algorithms, and the 'culture' of insulin use in the hospital."
Study Details
The included 166 adults (42% minority race or ethnicity, 28% women) with type 2 diabetes or an HbA1c of greater than 7.0% if previously undiagnosed who were treated or planned for treatment with insulin and expected to need non-ICU care at the hospital for more than 3 days.
The intensive-treatment-target group was treated by the same glucose management team using a real-time CGM for management decisions on insulin delivery and safety monitoring, particularly for hypoglycemia. The management team was to follow institutional standard operating procedures with regard to glucose testing for administering mealtime insulin and corrections without relying on the CGM.
A blinded CGM sensor was also worn for data analyses by the standard-target group.
Of the 110 patients with sufficient CGM data to be included in the primary analysis, 7% of those in the intensive-control group actually achieved it – and 6% in the usual-care group achieved that target as well.
Mean baseline HbA1c was 8.9% in both groups, and the largest proportion of patients entered the trial at or above 9.0% (36% in the intensive group and 42% in the standard-treatment group).
There was a suggestion that an intensive control target helped bring down glucose in those with baseline below 9.0% (mean 161 vs 175 mg/dL). But the high-HbA1c group actually appeared to do better with standard control (174 vs 188 mg/dL).
What Went Wrong?
Intensive care unit (ICU) studies have generally failed to show a benefit of tight glucose control in a critically ill population, but targets for the general and surgical wards have been based solely on consensus with no randomized controlled trial data beyond glycemic measures.
"The most important question in contemporary diabetology, particularly inpatient diabetology, is whether controlling hyperglycemia to near normal levels is important for outcomes of a given hospitalization, especially in a non-critical care setting," Umpierrez acknowledged.
The hope was that leveraging CGM would allow tight control without the problems with hypoglycemia that have been seen as one reason prior intensive glucose management trials have failed in a hospital setting, said John Buse, MD, PhD, of the University of North Carolina at Chapel Hill, who was part of the trial steering committee.
"I think the most important learning that we got from this study is that in the future, we're going to have to differentiate patients based on what a perception of the opportunity would be to get tight glucose control," he told . Someone who comes to the hospital with chronically poor diabetes control might not be a good candidate, he said. "That may be too much change in glucose. There is some evidence that's a potential problem, and it also creates the need often to give really heroic doses of insulin, where hypoglycemia is clearly going to be an increased problem."
Nursing is key, Hirsch said. And without dedicated research nurses, protocols weren't standardized across the six U.S. participating sites. Nursing shortages after the COVID-19 pandemic and the widespread use of "travel nurses" meant many were not familiar with treatment algorithms, resulting in a major problem with timing prandial insulin at some sites.
He called for further inpatient, non-ICU trial research to look not only at glycemic outcomes but length of stay and other clinical endpoints.
The TIGHT trial provided long awaited data, agreed audience member Archana Sadhu, MD, of Houston Methodist Hospital. "As disappointing as it is and as many holes as we can find that it didn't give the outcome we wanted, you really did just show what happens in the real world. So even if we had intensive research nurses and coordinators and we found a good outcome, this is what would happen when we universalize to practice. So that is useful."
Disclosures
The trial was funded by Dexcom.
Hirsch disclosed relationships with Abbott, Roche, Hagar, Vertex, Embecta, Dexcom, and Tandem.
Umpierrez disclosed relationships with Dexcom, Abbott, Bayer, and AstraZeneca.
Buse disclosed relationships with most companies in the diabetes space.
Sadhu disclosed serving on an advisory panel for Abbott Diagnostics.
Primary Source
American Diabetes Association
Draznin B, et al "Results from a randomized trial of intensive glucose management using continuous glucose monitoring (CGM) versus usual care in hospitalized adults with type 2 diabetes -- the TIGHT study" ADA 2024.