Background: There is increasing interest in using CGM for the inpatient management of diabetes in non-ICU settings. Current industry guidelines recommend removing devices when undergoing certain radiology procedures due to concerns about potential interference with CGM system functioning. However, there is no published data on the impact of CGM precision and accuracy after radiation and contrast exposure to support this recommendation.
Methods: We collected data on 49 adult medicine and surgery patients with type 1 and type 2 diabetes who were monitored with Dexcom CGM systems before and after radiology procedures (x-rays, CT scan, catheterization/angiography). The primary outcome was glycemic variability by percent coefficient of variation (%CV) as reported by CGM 2-hours pre and post imaging. Secondary outcome was the mean absolute relative difference (MARD) between matched glucose pairs from capillary point-of-care and CGM pre and post imaging procedure.
Results: There were no significant differences in mean blood glucose (BG) or %CV seen on CGM readings for all imaging procedures combined (delta mean BG -7.7 ±26.0, p=0.051; %CV 18.0% pre vs. 19.1% post, p=0.65) or when stratified by x-ray (delta mean BG -8.8 ±29.9, p=0.15; %CV 20.1% pre vs. 21.5% post, p=0.60) vs. CT scan/catheterization/angiography (delta mean BG -6.3 ±20.6, p=0.19; %CV 15.2% pre vs. 15.9% post, p=0.97). The overall MARD was 13.3% pre-imaging and 12.7% post-imaging. The overall percentage of glucose values within ±15%/15mg/dl, ±20%/20mg/dl, and ±30%/30mg/dl of the POC reference value was 69%, 80%, and 94%, respectively pre-imaging, and 69%, 82% and 93% post-imaging (p=NS). Clarke Error Grid analysis showed 98.1% of glucoses falling into Zones A and B pre-imaging and 99.7% post-imaging.
Conclusions: Preliminary data suggests that ongoing CGM usage during multiple radiology procedures is safe and reliable without interference or disruption in CGM data transmission.
A. Migdal: None. E. Spanakis: Research Support; Self; Dexcom, Inc. R.J. Galindo: Advisory Panel; Self; Lilly Diabetes. Consultant; Self; Valeritas, Inc. Research Support; Self; Novo Nordisk Inc. Other Relationship; Self; UpToDate. G. Davis: None. L.G. Singh: None. M. Satyarengga: None. M. Fayfman: None. F.J. Pasquel: Advisory Panel; Self; AstraZeneca, Eli Lilly and Company. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Merck Sharp & Dohme Corp. Research Support; Self; Dexcom, Inc., Merck Sharp & Dohme Corp., National Institutes of Health. B.S. Albury: None. M.A. Urrutia: None. K.W. Zamudio: None. S. Gibanica: None. S. Cardona: None. L. Peng: None. G.E. Umpierrez: None.