Superior T1D Control Seen With HCL Systems vs SAP Therapy in Older Adults

An analysis of data on 37 patients living with type 1 diabetes (T1D) who received hybrid closed-loop (HCL) insulin delivery and sensor augmented pump (SAP) therapy for 16 weeks each shows that treatment with an HCL system is more likely to lead to superior glycemic control in a safe manner—the risk of hypoglycemia did not increase. T1D can be especially difficult to manage in older adults, due to complications and comorbidities that accompany advanced age and long disease duration, the study investigators noted.

The results of this open-label, multicenter, multinational, randomized, crossover investigation were recently published in The Lancet: Health Longevity. Recruitment took place between September 4, 2019, and October 2, 2020, at diabetes outpatient clinics in the United Kingdom (3 centers) and Austria (1 center). Participants could not have a history of closed-loop system use or more than 1 hypoglycemia event in the 6 months leading up to their study enrollment.

“Severe hypoglycemia remains a common occurrence in this population,” the study’s authors wrote. “The ability to manage technology and devices in older adults might not be as widespread as in younger people and high-quality evidence for the safety and efficacy of closed-loop technology in older adults is scarce.” Their primary end point was proportion of time spent in the target glucose range of 3.9 to 10.0 mmol/L, and secondary end points included time spent in hyperglycemia, mean glucose, total daily insulin units, and glucose coefficient of variation.

Those using an HCL system spent more mean (SD) time in the targeted glucose range compared with those on SAP therapy, for an overall bump of 12% more time, or 8.6 percentage points (95% CI, 6.3-11.0):

• HCL group: 79.9% (7.9%)
• SAP therapy group: 71.4% (13.2%)

A 4-week washout period divided the treatment periods.

Overall, the median (IQR) patient age was 68 (63-70) years, their mean (SD) baseline glycated hemoglobin was 7.4% (0.9%) (57 [10] mmol/mol), 97% of participants were White, 57% were male, median (IQR) diabetes duration was 38 (32-47) years, and the most common diabetes-related complication was neuropathy in 27%.

Time spent in hypoglycemia range (< 3.5 mmol/L and < 3.0 mmol/L) did not differ between the interventions, but there was significantly less time spent in severe hyperglycemic range (> 16.7 mmol/L) in the HCL group vs the SAP group, respectively:

• < 3.5 mmol/L: 0.7% (0.5%-1.1%) vs 0.7% (0.4%-1.2%) (P = .69)
• < 3.0 mmol/L: 0.2% (0.1%-0.3%) for both (P = .69)
• > 16.7 mmol/L: 0.5% (0.2%-0.8%) vs 0.8% (0.2%-2.8%) (P < .0001)

In addition, HCL system use resulted in superior overnight glucose control compared with daytime control, as measured by more time spent in the target range and less time spent in a hypoglycemic state while sleeping vs during the daytime:

• Overnight glucose control: 86.8% (8.7%)
• Daytime glucose control: 77.6% (8.0%)
• Nighttime hypoglycemia: 0.9% (0.5%-1.6%)
• Daytime hypoglycemia: 2.0% (1.5%-2.7%)

There were 2 instances of severe hypoglycemia during SAP use, but no instances of diabetic ketoacidosis. COVID-19 led to the death of 1 participant and to parenteral hydrocortisone use in another because of adrenal insufficiency during the run-in period, the authors noted.

“The present study shows it is possible to achieve excellent glycemic control by means of an HCL system without increasing the risk of hypoglycemia above that of SAP therapy in older adults,” the authors concluded. “These outcomes compare favorably with those of studies of younger adults and children with type 1 diabetes and they support the adoption of closed-loop therapy in older adults with type 1 diabetes in clinical practice.”

Study strengths include the high retention rate, high treatment adherence, and few protocol deviations. Limitations on generalizability to a wider patient population include the lack of ethnic diversity, high overall educational level, and possible higher level of technical proficiency.

Reference

Boughton CK, Hartnell S, Thabit H, et al. Hybrid closed-loop glucose control compared with sensor augmented pump therapy in older adults with type 1 diabetes: an open-label multicentre, multinational, randomised, crossover study. Lancet Healthy Longev. 2022;3(3):e135-e142. doi:10.1016/S2666-7568(22)00005-8