Continuous Glucose Monitoring Reduces Hypoglycemia in Older Adults with Type 1 Diabetes

Press Release – June 16, 2020

Study Highlights:

  • Six-month clinical trial shows the use of continuous glucose monitoring (CGM) reduces serious levels of hypoglycemia (low blood sugar), compared with standard monitoring by daily use of blood glucose finger-stick test strips.
  • CGM users saw significant reductions in the amount of time spent in hypoglycemia and in the occurrence of severe hypoglycemic events while also improving their hemoglobin A1C levels and overall glucose control. 

Ann Arbor, Michigan – June 16, 2020 – Older adults with type 1 diabetes (T1D), a growing but under-studied population, are prone to hypoglycemia, particularly when diabetes is longstanding. Hypoglycemia can cause altered mental status and sometimes seizure or loss of consciousness which can prove fatal. But older adults who use continuous glucose monitoring (CGM) devices can significantly reduce the occurrence of hypoglycemia and severe hypoglycemic events while also reducing hemoglobin A1c, according to findings from a 6-month, multi-center clinical trial. The study was published online on June 16 by the Journal of the American Medical Association (JAMA).

The objective of the study was to determine if the use of CGM can reduce hypoglycemia among older adults with type 1 diabetes. A CGM device continuously measures blood sugar and provides real-time observation of glucose levels, trend direction and alarms for when glucose drops to low levels or increases to high levels.

“Reducing hypoglycemia is an important aspect of management of T1D in older adults, many of whom have difficultly recognizing symptoms of hypoglycemia cognitive impairment, or both. The potential benefit of CGM in reducing hypoglycemia in the older adult population had not been well studied. Although CGM devices have been available for over a decade, Medicare did not begin covering CGM until 2017,” says lead study author Richard Pratley, Samuel E Crockett Chair in Diabetes Research and Diabetes Program Lead at the AdventHealth Translational Research Institute in Orlando, FL.

The study was a randomized, controlled trial involving 203 men and women over the age of 60 years at 22 clinical centers, including Michigan Medicine. About half of participants were receiving insulin via an insulin pump and the other half used multiple daily injections of insulin. Participants were randomly assigned to a group using a Dexcom CGM devices (n=103) or to a control group using the standard finger-stick method with test strips for blood glucose monitoring (n=100) for six months.

The study found that the amount of time glucose levels were in a hypoglycemia range (< 70 mg/dL) was reduced from 73 minutes per day at the start of the study to 39 minutes per day in the group using CGM for a 6-month period; whereas for people in the control group, their average minutes per day in hypoglycemia was 68 minutes per day at the start of the study and 70 minutes per day over the six-month study period. Researchers also found:

  • CGM users were far less likely to have a severe hypoglycemic event compared to the control group using blood glucose meter checks; 10 participants in the control group had a severe hypoglycemic event compared with only 1 participant in the CGM group. 5 of the 10 severe hypoglycemic events reported in the control group involved seizure or loss of consciousness which did not occur in the 1 CGM group event.
  • Reducing hypoglycemia did not come at the cost of worsening overall glucose control. The average hemoglobin A1c (HbA1c, an estimate of blood glucose control over a 3-month period) for the CGM group improved from 7.6% at the start of the study to 7.2% at 6-months. The control group HbA1c was 7.5% at the start of the study and 7.4% at 6-months. The American Diabetes Association recommends an HbA1c target of < 7.0% for adults, but with less stringent targets for older adults prone to hypoglycemia.
  • Very low or very high blood glucose episodes can be dangerous. Regular CGM use increased the amount of time in target range (glucose levels of 70 mg/dL to 180 mg/dL) by more than two hours a day.

Another striking discovery was that 81% of study participants were still using the CGM devices 7 days per week at six months.

These results are important because they demonstrate CGM can be used effectively in an older adult population to reduce hypoglycemia as well as improve overall glucose control. Because hypoglycemia can lead to serious complications including hospitalization and death, the reduction in severe hypoglycemic events could have important public health implications.

“For too long, the older population with diabetes has suffered from not-so-benign neglect from the medical community,” says Rodica Pop-Busui, MD, PhD, Larry D Soderquist Professor of Diabetes and Professor of Internal Medicine in the Division of Metabolism, Endocrinology & Diabetes, who was the principal investigator at Michigan Medicine. “Despite the high prevalence of diabetes and its complications in this age group, very few studies have addressed the potential utility of new technologies in this population. In part, this may be due to the mistaken belief that older adults can’t manage or benefit from advanced technologies. Our study shows quite the opposite. Not only does CGM improve safety in older adults - which is huge - it actually improves overall glycemic control. Moreover, the overwhelming majority of patients in our study used CGM most days for the entire duration of the study, demonstrating a high level of comfort with the technology in this population.”

In addition, the treatment impact on reducing hypoglycemia at six months was present on those using insulin pump as well as those using multiple injections of insulin. The effective use of CGM in those using multiple injections of insulin has important implications as these patients likely will not make the switch to more advanced technologies that automate insulin.

“This study highlights the opportunity to target older patients who may be struggling with hypoglycemia by offering advanced technologies available today,” says Dr. Pop-Busui. “We are hopeful this will lead to better outcomes for this growing older adult population with type 1 diabetes.”

The study authors are: Richard Pratley, MD, Lauren G. Kanapka, MSc, Michael R. Rickels, MD, MS, Andrew Ahmann, MD, Grazia Aleppo, MD, Roy Beck, MD, PhD, Anuj Bhargava, MD, Bruce W. Bode, MD, Anders Carlson, MD, Naomi S. Chaytor, PhD, D. Steven Fox, MD, MPhil, Robin Goland, MD, Irl B. Hirsch, MD, Davida Kruger, MD, Yogish C. Kudva, MD, Carol Levy, MD, Janet B. McGill, MD, Anne Peters, MD, Louis Philipson, MD, PhD, Athena Philis-Tsimikas, MD, Rodica Pop-Busui, MD, PhD, Viral N. Shah, MD, Michael Thompson, MD, Francesco Vendrame, MD, Alandra Verdejo, MPH, Ruth S. Weinstock, MD, PhD, Laura Young, MD, PhD, Kellee M. Miller, PhD, MPH for the Wireless Innovation for Seniors with Diabetes Mellitus (WISDM) Study Group

Funding was provided by JDRF and The Leona M. and Harry B. Helmsley Charitable Trust.

CGM devices were provided by Dexcom, Inc. at no cost.