CGM benefits older adults with diabetes and dementia

medwireNews: Continuous glucose monitoring (CGM) may significantly reduce the risk for hospitalization and mortality versus self-monitoring of blood glucose (SMBG) in insulin-treated older adults with diabetes and Alzheimer disease or related dementias (ADRD), US research shows.

“Our study provides evidence supporting the clinical benefits of CGM use in potentially improving health outcomes for this vulnerable population,” write Jingchuan Guo (University of Florida, Gainesville) and co-authors in JAMA Network Open.

They used Medicare claims data from 2016 to 2020 to determine glycemic outcomes and adverse events among 2022 insulin-treated older adults with diabetes and ADRD (mean age 76 years, 56% women). The cohort included 1011 individuals who initiated CGM during the study period and 1011 prevalent SMBG users who were matched using propensity scoring.

During a median 1.9 years of follow-up, the researchers found that CGM users had a significantly lower rate of all-cause hospitalization than SMBG users (558 vs 653 events per 1000 person–years) and significantly lower all-cause mortality (145 vs 249 events per 1000 person–years).

After adjustment for demographic characteristics, comorbidity, and medication and healthcare use, CGM use was associated with a significant 14% lower risk for all-cause hospitalization, and a significant 43% lower risk for death.

The team also observed that, compared with SMBG users, those using CGM had lower rates of hypoglycemia hospitalization (17 vs 24 events per 1000 person–years) and falls (86 vs 98 events per 1000 person–years), and more hyperglycemia crises (57 vs 38 events per 1000 person–years), but the differences between the two groups did not reach statistical significance after adjustment for confounders.

Not all patients benefit equally from CGM

Subgroup analyses revealed that the benefits of CGM were not uniform. Specifically, the lower risk for all-cause hospitalization with CGM use was significant among people younger than 85 years (hazard ratio [HR]=0.87), non-Hispanic White people (HR=0.86), individuals with type 1 diabetes (HR=0.83), and those with severe frailty (HR=0.73) or severe comorbidity (HR=0.83), but not among other subgroups.

Male CGM users and people with severe comorbidity had significantly lower risks for hypoglycemia hospitalization than their SMBG using counterparts (HRs=0.35 and 0.52, respectively), but there was no significant benefit of CGM use with respect to this outcome in other subgroups.

While CGM use was associated with lower all-cause mortality risk across most age, sex, race and ethnicity, diabetes, frailty, and comorbidity subgroups (HR=0.47–0.69), there was no significant benefit among non-Hispanic Black and Asian and Pacific Islander individuals.

For hyperglycemia crisis, the risk was significantly elevated among CGM users with type 1 diabetes relative to SMBG users (HR=1.78), and among those with severe comorbidity (HR=1.53), with no significant differences in other subgroups.

Finally, CGM use was associated with a lower risk for falls in patients with type 1 diabetes (HR=0.61), but not in other subgroups.

Although the data “suggest that CGM use was associated with better long-term outcomes in older adults with diabetes and ADRD compared with SMBG use,” Guo et al note that “the inherent limitations of claims-based observational studies, especially the lack of glycemic data and the level of social support,” mean that prospective clinical trials are needed to confirm their results.

Critical data could lead to expanded CGM use in patients with cognitive decline

In an accompanying comment, Thaer Idrees (Emory University School of Medicine, Atlanta, Georgia, USA) and Elena Toschi (Harvard Medical School, Boston, Massachusetts, USA) describe the findings as “critically needed.”

They say: “The results are promising, and clinicians and policymakers should expand the use of CGM in this population with cognitive decline.”

However, like Guo et al, the commentators acknowledge that “prospective studies are needed to provide additional data on the benefits of CGM in this frail, high-risk population and to develop clinical pathways to support clinicians and caregivers on the use of CGM in patients with ADRD.”

They add: “Such studies will provide further evidence to support the benefits of CGM on overall and geriatric-related clinical outcomes, supporting the need for policy change to expand coverage and improve access to CGM in this older population with diabetes and cognitive decline.”

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JAMA Netw Open 2025; 8: e2541939
JAMA Netw Open 2025; 8: e2541947