Introduction: Patients with complicated type 1 diabetes mellitus (T1DM) who were eligible for islet cell transplant (ICT) already have a significant comorbidity burden prior to transplant with a high mortality risk. Technological advancements, including continuous glucose monitoring (CGM) and insulin pump technology, minimise life threatening hypoglycemia and optimise secondary cardiovascular event prevention. 

Methods: A retrospective study of patients with T1DM who had been referred for ICT or simultaneous islet kidney transplant (SIK) at Manchester Royal Infirmary was conducted to evaluate differences in pre-transplant diabetes management between those patients who have successfully been transplanted compared to those who died whilst awaiting for a transplant or during the assessment period. 

Results: Twenty patients who had ICT were compared to thirty patients who died whilst waiting for transplant or during the assessment period. Data was tested for normality using the Shapiro-Wilks normality test. Parametric (T-test), Non-parametric (Mann-Whitney) or Chi Sq were performed to determine differences between groups with P<0.05 determined to be significant. There were no significant differences between the group who were transplanted compared to those who died in mean age (55.1±3.0 vs. 55.8±2.0 years, P=0.8), sex (55% vs. 37% female, p=0.16), ethnicity (all white), T1DM duration (36.1±2.3 vs. 33.8±2.0 years, P=0.5), weight (78.1±3.5 vs. 70.3±2.7 kg, P=0.2) HbA1c (63.4±3.2 vs 62.8±1.7 mmol/mol, P=0.9) or daily insulin dose (37.1±2.3 vs. 40.2±2.8 units, P=0.7). There were no significant differences in the prevalence of end stage renal failure, diabetic retinopathy or cardiovascular disease.  
Nineteen patients in the transplanted group had been using CGM with an average duration of use of 56 months, with only one patient using finger-prick testing. In the cohort that died prior to transplantation, 10 out of 30 patients had been using CGM (mean duration:20 months). The percentage using CGM in the transplanted group was significantly higher (95% vs 33.3 %, P<0.001). In the group who died mean time on the list was 41 months in those on CGM compared to 26 months in those without. 
Seven out of 20 patients in the transplanted group were managed with insulin pumps while 5 out of 30 patients in the group that died were managed using insulin pumps. Whilst 7 patients’ hypoglycemic awareness improved with CGM/insulin pump in the transplanted group, there was only one patient whose hypoglycemic awareness improved in the group that died prior to transplantation.  

Conclusion: The utilization of CGM and insulin pump therapy was lower in the group who died prior to having a transplant. NICE recommends use of CGM for all patients with T1DM. These results support the use of technology as for the management of this high-risk group of patients to improve the likelihood of survival to transplantation. Further detailed analysis of the CGM data  in these groups is warranted.