Overestimation of hypoglycaemia diagnosis by FreeStyle Libre continuous glucose monitoring in long-term care home residents with diabetes.
You are not Logged in
• Thirteen residents with Type 2 diabetes and on multiple daily insulin injections (6 women, 7 men, mean±SD age: 85.6±8.6 years) were prescribed FreeStyle Libre (Abbott France S.A.S. Abbott Diabetes Care, Rungis, France).
• The FreeStyle Libre sensor was inserted under the posterior face of the arm and replaced every 2 weeks for up to 10 months. It was scanned before each insulin injection and meal and at 10 p.m. and 4 a.m.
• Nurses were asked to measure capillary blood glucose (BG) using the BG meter built into the reader at the same time as every interstitial glucose (IG) scan during the first week and later on only when IG was below 70 mg/dL.
• The FreeStyle Libre system was well tolerated in 9 residents and withdrawn by 4, with no difference in cognitive impairment or dementia.
• Comparing 302 paired BG and IG measurements revealed a tight correlation (linear regression: r=0.955, p<0.0001, IG=1.022BG–19.06).
• Mean IG was significantly lower than mean BG with a mean absolute relative difference (MARD) of 19.7%. Out of 144 IG lower than 70 mg/dL, 74 (51.4%) were associated with BG equal or higher to 70 mg/dL. In the group experiencing false hypoglycaemia, IG was significantly lower than BG (56.8±8.7 vs. 89.6±15.6 mg/dL, p<0.0001). Mean IG was significantly lower than BG for the 70–180 mg/dL BG group, with a MARD of 25.5%, and did not differ from BG in the >180 mg/dL BG group, with a MARD of 11.4%.
• Inaccuracy of the FreeStyle Libre system in the lower glucose values, possibly due to age-induced skin changes, is a barrier in the detection of hypoglycaemia risk in older residents in this study.
• IG lower than 70 mg/dL in the absence of clinical signs needs capillary BG measures, thus reducing the FreeStyle Libre system’s benefit on patients’ comfort.
• Improvement in performance in the low and middle IG range is of clinical relevance for reliable detection of hypoglycaemia and better evaluation of diabetes control.
• The ability to fix the upper target glucose at 200 mg/dL instead of 180 mg/dL should also be included since 100–200 mg/dL is the BG target range in this population.
• It is suggested that hypoglycaemia diagnosis by the FreeStyle Libre system in long-term care home residents with diabetes may be overestimated.