Use of CGM in Kidney Transplant Recipients

Diabetes is one of the leading causes of End Stage Renal Disease (ESRD). Kidney transplantation is the best form of renal replacement therapy to date but requires that recipients of transplant organs maintain a complicated medication regimen in order to prevent graft loss. Their medications include lifelong immunosuppression, anti-microbials and other maintenance medications (i.e., anti-hypertensives, heart-protective regimens, bowel care, vitamins and pain medications).

For many transplant patients, glycemic control in the immediate post-operative period can be an additional challenge. Glycemic control may be hindered by recent surgery, corticosteroids, immunosuppressants, altered nutritional intake and reduced mobility.

Diabetes professional organizations such as the American Diabetes Association (ADA) and the American Association of Clinical Endocrinologists (AACE) recommend continuous glucose monitoring (CGM) for anyone on intensive insulin therapy. The biggest benefit of CGM is not just the actual glucose value, but also its direction and rate of change. CGM data can also be downloaded and reflect patterns of glycemic control throughout the day and night, including not only the average blood glucose but also time-in-range (TIR) and degrees of glycemic variability. This can help identify unnotified nightly hypoglycemia or hyperglycemia and help titrate medications to achieve better glycemic control. Self-Management of blood glucose (SMBG) is a key component in effective glycemic management, but it places a large burden on the patient. Prior to CGM, SMBG was the only option to measure daily blood glucose fluctuations, but it is an imperfect tool. For patients on insulin, a blood glucose is checked at minimum 4 times per day, prior to meals and at bedtime. Additionally, the utility of SMBG can be endangered by patient decision making, the ability to check blood glucose, adherence to testing regimen, error due to poor testing technique, inadequate blood supply, contamination on fingers, or inaccuracy of some systems.

Numerous studies have shown the clinical benefit of CGM in the type-1 diabetes (T1D) and type-2 diabetes (T2D) populations (ref: Beck, Olafsdottir). The DIAMOND group (Beck) showed that CGM improved HBA1C and reduced hyperglycemia (BG>180). Patients wearing the CGM had high satisfaction scores and low perceived burden. CGM is still a new tool outside of the Type 1 Diabetes population but may have significant benefits for any patient on insulin. In Feb 2019 an international guideline on TIR (defined as blood glucose of 70-180 mg/dL) was published and TIR may become a new standard for assessing glycemic control.

The investigators research focuses on TIR and the benefits of CGM in the kidney transplant population. This can be essential for timely adjustments of insulin dosages when dealing with glycemic derangements and steroid induced hyperglycemia. CGM can provide an immense opportunity for a continuous 24/7 view of glucose values, glycemic variability, direction of change and unrecognized blood glucose levels during nighttime, and influence of food and activity on blood glucose values. In addition to the metrics described; the glucose management indicator (GMI) or also named estimated A1C (eA1C) is a measure converting the mean glucose from CGM using a formula derived from glucose readings from a population of individuals, into an estimate of a simultaneously measured laboratory A1C, this value may serve as an additional tool in assessing glycemic control. In conclusion: the use of a CGM can aid the provider and care team in better titration of insulin and medication regimen adjustment. This research hopes to give insight in a very complex population that has not had access to CGM before.

Inclusion criteria

• Age 18 or above
• Received a kidney transplant within the past year with functioning kidney (eGFR > 30 mL/min
• Person with Type 2 Diabetes and on insulin
• Access to home wi-fi connection

Exclusion criteria

• Person with Type 1 Diabetes
• Patients taking hydroxyurea
• Patient unable to wear the Dexcom G6 device at all times for any reason
• Must be able to test blood glucose with meter 4x a day when on blinded CGM.
• Presence of clinically significant visual or cognitive impairment
• Illiterate
• Prisoners
• Women who are pregnant, who plan to become pregnant during the course of the study, or who are breastfeeding
• Presence of clinically unstable cardiovascular disease
• Active malignancy treatment