Continuous glucose monitoring system for early detection of graft dysfunction in allogenic islet transplant recipients.
BACKGROUND
There are no effective indicators of graft dysfunction in islet transplantation. This study evaluated the role of the Continuous Glucose Monitoring System (CGMS) as an early indicator of graft dysfunction in islet transplant recipients.


METHODS
In 5 islet allograft recipients, we retrospectively determined the date of graft dysfunction: 3 fasting blood glucose levels >7.8 mmol/L (140 mg/dL) and/or 3 postprandial blood glucose levels >10 mmol/L (180 mg/dL) in 1 week. We then determined 2 time points in respect to graft dysfunction, 5 to 9 months before (time point A) and 2 to 3 months before (time point B). For these 2 time points, we assessed the following: HbA1c, C-peptide (CP), C-peptide glucose ratio (CPGR), 90-minute glucose from mixed meal tolerance test, and percentage of capillary blood glucose levels >7.8 mmol/L (%CBG >7.8) in a 15-day interval (1 week before and after CGMS placement). From the CGMS recordings, we calculated the glucose variability and the percentage of time spent in hyperglycemia >7.8 mmol/L (%HGT >7.8) and >10 mmol/L (%HGT >10).


RESULTS
No difference was found between time points A and B for the following parameters: HbA1c, CP, CPGR, 90-minute glucose, %CBG >7.8, and %HGT >10. We observed a statistically significant increase from time point A to time point B in glucose variability (1.1 +/- 0.5 mmol/L to 1.6 +/- 0.6 mmol/L; P = .004), and in the %HGT >7.8 (11 +/- 12% to 22 +/- 18%; P = .036).


CONCLUSIONS
Glucose variability and %HGT >7.8 determined using CGMS are useful as early indicators of graft dysfunction in islet transplant recipients. Further studies with larger sample sizes will help validate these observations.
Faradji
R N
RN
Diabetes Research Institute, University of Miami-Miller School of Medicine, Miami, Florida 33136, USA.
Monroy
K
K
Riefkohl
A
A
Lozano
L
L
Gorn
L
L
Froud
T
T
Cure
P
P
Baidal
D
D
Ponte
G
G
Messinger
S
S
Mastrototaro
J
J
Ricordi
C
C
Alejandro
R
R
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002096:C-Peptide / Q000097:blood; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016381:Islets of Langerhans Transplantation / Q000473:pathology / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods*; D008991:Monitoring, Physiologic / Q000379:methods*; D011183:Postoperative Complications / Q000097:blood; D012189:Retrospective Studies; D014184:Transplantation, Homologous
D001786:Blood Glucose; D002096:C-Peptide; D007166:Immunosuppressive Agents