Few older patients with type 1 diabetes established on sensor-augmented insulin pump therapy meet all CGM-based consensus recommendations modified for older adults.
However glucose time in range far exceeded the consensus minimum target of 50% for older adults, and no hypoglycaemia-related clinical events occurred among the functionally independent participants.
A post-hoc analysis was conducted on prospective data from 30 patients aged ≥60 years before their randomisation in the Older Adult Closed Loop (ORACL) trial.
The Australian study, published in The Lancet Healthy Longevity [link here], found the median CGM time in range 3·9–10·0 mmol/L was 71%.
Time spent with glucose above 10·0 mmol/L was 27% and above 13·9 mmol/L was 3·9%; time with glucose below 3·9 mmol/L was 2·0% and the time below 3·0 mmol/L was 0·2%.
“The median glucose time below range was equivalent to 29 min per day, whereas the consensus-recommended older adult glucose time-below-range target is less than 14 min per day,” it said.
The study also found time spent in hypoglycaemia was lower among the 16 participants with predictive low alert enabled than among the 14 participants not using predictive low alerts (1·5% v 2·7%; p=0·038).
“As the use of CGM predictive low alerts was associated with a lower median glucose time below range by almost half, and by seven times overnight, such predictive alerts are likely to be important for minimising hypoglycaemia.”
Only two of 30 participants (7%) met all four age-modified glucose targets.
“Our results show that current CGM-based targets recommended for all older adults, without consideration of frailty status, are not suitable for cognitively healthy and functionally independent individuals without frailty,” the study said.
“We suggest that alternative CGM-based targets might be appropriate for relatively healthy, robust, and independent older individuals, such as most of the individuals in this study, and that access to diabetes therapeutic technology should be considered when determining CGM-based targets.”
The investigators, led by Dr Steven Trawley from the University of Melbourne, concluded that glucose time in range and hypoglycaemia readings were achievable with sensor-augmented pump therapy for older adults without frailty.
A Comment in the journal [link here] said evidence-based CGM targets for older adults were required.
These should be “updated to align with HbA1c target recommendations, and individualised based on frailty, functional status, and use or non-use of sensor-augmented pump therapy or closed-loop systems.”
Currently, the optimal time below range threshold for older adults, and whether this differs from the general adult population, was unknown, the author said.
“A so-called hierarchical approach to CGM targets for older adults might be prudent, in which achievement of the time below range target is first prioritised, followed by maximising the time in range, but without sacrificing greater time below range.”
“Further studies should be done to clarify the optimal time below range thresholds among frail and non-frail older adults, to minimise the risks of clinically significant or severe hypoglycaemia in the older adult population.”