Continuous Glucose Monitoring (CGM) in Kidney-Transplanted Adults

Study Overview
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Brief Summary
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Pre-existing diabetes prior KT and Early Post-Transplant Hyperglycemia (PTRH) defined as a fasting blood glucose greater than or equal to 126 mg/dL or random glucose greater than or equal to 200 mg/dL or requirement of insulin during the first 45 days after KT has been associated with increased risks of post-transplant organ rejection. PTRH has also been associated to high infection rates, and in some cases, early mortality. The use of continuous glucose monitoring (CGM) compared with blood glucose meter monitoring in non-transplant patients with diabetes resulted in lower HbA1C by 0.4 to 0.5% within the first three months of use without major changes in patients' antidiabetic regimen, possibly due to patients become more conscious about their diabetes status and diet. CGM free style libre-2 measures the interstitial fluid every minute and their glucose sensors are replaced every two weeks. To our knowledge there are no studies that assess the role of CGM in improving glycemic and transplant outcomes in solid organ transplant patients, mainly because access to CGM is often limited by inadequate health insurance coverage or high out-of-pocket costs. The investigators hypothesize that the intervention will be feasible and acceptable to patients, and our overarching hypothesis is that patients who wear a CGM will have better glycemic control, using a proxy measure of lower fructosamine/albumin ratio and better CGM-parameters, compared to those who did not wear it. Fructosamine represents the average glycemia for the 2 to 3 weeks prior. It is useful in any situation where glycemic control needs to be assessed over a period shorter than a month and in cases involving interference in the HbA1C measurement such as in adults with KT due to shorter red blood cell lifespan related to anemia of chronic disease. Fructosamine values vary in relation to the serum albumin concentration, which makes the fructosamine/albumin ratio the ideal physiologic measure for this pilot study . The investigators also hypothesize that patients who wear a CGM will have less microalbuminuria compared to those who did not wear it.

Detailed Description
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Diabetes is a leading cause of end-stage renal disease, which is treated by undergoing kidney transplantation. Glycemic control post-transplantation is complicated for the diabetic population by a complicated medication regimen that suppresses immunologically-driven graft loss but increases glucose levels. Hyperglycemia in this transplant population results in transplant failure. Improving glycemic control in the diabetic kidney transplant population may decrease kidney transplantation failure rates. Continuous glucose monitors have been shown to improve glycemic control among insulin-dependent diabetics. Therefore, the investigators aim to assess the feasibility and acceptance of continuous glucose monitoring among diabetic kidney transplant patients. This is an open-label, randomized, crossover design study comparing diabetic, kidney-transplant recipients managing their diabetes with a continuous glucose monitor or glucometer. Eligible participants will engage study staff during regularly scheduled, standard of care, post-operative visits. Utilization of the CGM will be assess to determine the feasibility of CGM usage in this population. Participants will complete validated quality-of-life surveys (Diabetes Treatment Satisfaction Questionnaire (DSTQ) and Hypoglycemic Confidence Scale (HSC)) throughout the 32 weeks study regimen to inform the acceptability of CGM usage. Glucose records, provided by glucose meters and CGMs that report glucose readings to either the participant or clinic will be leveraged to estimate if CGM usage decreases hyperglycemia among diabetic kidney-transplant recipients. Results from this study will be foundational towards assessing if CGM usage improves glycemic control among diabetic kidney-transplant recipients, improves transplant outcomes and, hopefully, triggering health insurance providers to reassess the return on investment of subsidizing continuous glucose monitoring in the kidney-transplant population.

Official Title
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Continuous Glucose Monitoring (CGM) in Kidney-Transplanted Adults

Conditions
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Diabetes Mellitus, Kidney Transplant; Complications

Intervention / Treatment
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* Device: Free style libre-2


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients older than 18 years patients with history of diabetes (either T1D, T2D or atypical diabetes forms) patients could be on insulin or not before transplantation Exclusion Criteria: kidney-pancreas transplanted participants not currently using CGM (but could have used a year prior the transplant) mental conditions that prevent continuing with the study.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Continue Glucose Monitoring (CGM)<br>External diabetes device glucose sensor that measures interstitial glucose levels every minute | Device: Free style libre-2<br>* A cross-over design will allow estimation of feasibility and acceptability of patients using CGM vs patients using blood glucose meter monitoring (conventional therapy). The study will consist on two phases, the first will last three months, then it will be a two months of washout period followed by the crossover, then the second phase will last another three months. Patients in the conventional therapy group will also use masked CGM (CGM professional) during the first two and last two weeks of their study phase with the purpose of collecting CGM-parameters information. The cross over randomization will be stratified by donor type (live vs deceased) using a web-based randomization tool. During the washout period the patients will continue using blood glucose meter monitoring<br>|
| Other: Glucometer<br>Device that measures capillary blood glucose levels | Device: Free style libre-2<br>* A cross-over design will allow estimation of feasibility and acceptability of patients using CGM vs patients using blood glucose meter monitoring (conventional therapy). The study will consist on two phases, the first will last three months, then it will be a two months of washout period followed by the crossover, then the second phase will last another three months. Patients in the conventional therapy group will also use masked CGM (CGM professional) during the first two and last two weeks of their study phase with the purpose of collecting CGM-parameters information. The cross over randomization will be stratified by donor type (live vs deceased) using a web-based randomization tool. During the washout period the patients will continue using blood glucose meter monitoring<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compliance | To determine the feasibility and acceptance of CGM in adults with diabetes who underwent kidney transplantation compared to those who use glucometers. | 32 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| fructosamine/albumin ratio | glycemic marker | 20 weeks | 
| fructosamine/albumin ratio | glycemic marker | 32 weeks | 
| microalbuminuria | kidney function marker | 20 weeks | 
| microalbuminuria | kidney function marker | 32 weeks | 
| Glucose Management Indicator (GMI) | glycemic marker | 20 weeks | 
| Glucose Management Indicator (GMI) | glycemic marker | 32 weeks | 
| Time in Range (TIR) of 70 to 180 mg/dL | glycemic marker | 20 weeks | 
| Time in Range (TIR) of 70 to 180 mg/dL | glycemic marker | 32 weeks |