Assessment of the Accuracy of Continuous Glucose Sensors in People With Diabetes Undergoing Haemodialysis (ALPHA)
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ClinicalTrials.gov Identifier: NCT03885362 |
Recruitment Status :
Recruiting
First Posted : March 21, 2019
Last Update Posted : October 22, 2020
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Diabetic Nephropathies Type 1 Diabetes Mellitus Chronic Kidney Diseases | Device: Dexcom G6 and Abbott Freestyle Libre | Not Applicable |
Diabetic nephropathy is the leading cause of end-stage renal failure (ESRF), representing approximately 40% of people requiring long-term renal replacement therapy and maintenance haemodialysis [1]. Mortality and morbidity within this cohort is high, with the predominant cause being cardiovascular disease (CVD) [2]. Glycaemic control in many haemodialysis dependent patients with diabetes is poor and may lead to additional renal complications, including high interdialytic weight gain, electrolyte imbalance, and amputations [3]. Current clinical guidance is centred around the prevention of hyperglycaemia and microvascular complications of diabetes.
Glucose self-management is particularly challenging due to cyclical changes in insulin sensitivity and circulating insulin concentrations. Hypoglycemia is common due to impaired renal gluconeogenesis, malnutrition, and the increased half-life of insulin and hypoglycemic agents [4, 5]. Additionally, people with chronic kidney disease and diabetes may have other diabetes complications such as retinopathy, neuropathy, and impaired awareness of hypoglycaemia, which can make self-management more difficult.
Overall assessment of glycaemic control is also more complex as classical markers of glycemic control (i.e. HbA1c and fructosamine) may be misleading due to the variable underestimation of glycaemia resulting from analytical interferences, shortened half-life of red blood cells and abnormal albumin level [6-8]. Further limitations of HbA1c is that it is not informative regarding glycemic control on the days on and off dialysis, and intra-day glycaemic variability.
Frequent capillary blood glucose tests or self-monitoring of blood glucose (SMBG) is the traditional and one of the most effective ways to track an individuals' blood glucose levels. Real-time continuous glucose monitoring (CGM) has been shown to improve overall glucose control, reduce hypoglycaemia in people with an HbA1c <7.0%, and may reduce severe hypoglycaemia [9-11]. In addition, they provide alert and alarm features for hypo- and hyperglycaemia, and for times of rapid glucose change.
Flash glucose monitoring does not provide real-time data with alerts and alarms, but allows users to retrospectively review the preceding 8 hours of continuous glucose data, along with a contemporary estimated blood glucose value and trend line. The system consists of a subcutaneous sensor placed on the back of the upper arm, which measures glucose in the interstitial fluid every minute. The glucose data are made available when the user chooses to swipe the reader over the sensor.
CGM has the potential to reduce HbA1c and minimize exposure to hypoglycaemia while addressing diabetes distress. Flash glucose monitoring may reduce exposure to hypoglycaemia in people with insulin-treated diabetes.
The accuracy of CGM and flash in people with diabetes on haemodialysis has not been described. In this clinical study, we will assess the accuracy of the Dexcom G6 CGM system and the Abbott FreeStyle Libre flash system compared to YSI (Yellow Spring Instruments) glucose in people undergoing haemodialysis.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 40 participants |
Allocation: | N/A |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Masking Description: | Blinded CGM but not Libre |
Primary Purpose: | Prevention |
Official Title: | Assessment of the Accuracy of Continuous Glucose Sensors in People With Diabetes Undergoing Haemodialysis |
Actual Study Start Date : | December 11, 2019 |
Estimated Primary Completion Date : | September 2021 |
Estimated Study Completion Date : | September 2021 |

Arm | Intervention/treatment |
---|---|
Experimental: Dexcom G6 and Abbott Freestyle Libre
Participants will have a Dexcom G6 sensor and Abbott FreeStyle Libre sensor inserted in the abdomen and upper arm respectively. Participants will be asked to swipe the FreeStyle Libre reader across the sensor a minimum of every 8 hours. Participants will be asked to continue their usual regimen of self-monitoring capillary blood glucose (SMBG). During haemodialysis, a dialysis circuit blood sample will be drawn at 0 (pre-dialysis) 30, 60, 90, 120, 150, 180, 210 and 240 minutes and immediately after dialysis. Samples from the circuit will be analysed on the YSI glucose analyser. Participants will be asked to change the FreeStyle Libre sensors at day 14. The blinded CGM data will be uploaded at the time of each sensor change by the research team. |
Device: Dexcom G6 and Abbott Freestyle Libre
Dexcom G6 - continuous glucose monitoring device - blinded. CE mark 2018 Abbott Freestyle Libre - flash glucose monitoring device. CE mark 2014 |
- MARD between G6 and YSI [ Time Frame: 28 days ]Mean absolute relative difference between Dexcom G6 and YSI glucose during haemodialysis
- MARD between Libre and YSI [ Time Frame: 28 days ]Mean absolute relative difference between Dexcom G6 and YSI glucose during haemodialysis
- HbA1c [ Time Frame: 28 days ]Glycated Haemoglobin
- MARD for G6 and YSI <3.9mmol/L [ Time Frame: 28 days ]Mean absolute relative difference between Dexcom G6 and YSI glucose <3.9mmol/L
- MARD for Libre and YSI <3.9mmol/L [ Time Frame: 28 days ]Mean absolute relative difference between Libre and YSI glucose <3.9mmol/L
- MARD for Libre and YSI 3.9-10mmol/L [ Time Frame: 28 days ]Mean absolute relative difference between Libre and YSI glucose 3.9-10mmol/L
- MARD for Libre and YSI >10mmol/L [ Time Frame: 28 days ]Mean absolute relative difference between Libre and YSI glucose >10mmol/L
- MARD for G6 and YSI 3.9-10mmol/L [ Time Frame: 28 days ]Mean absolute relative difference between Dexcom G6 and YSI glucose 3.9-10mmol/L
- MARD for G6 and YSI >10mmol/L [ Time Frame: 28 days ]Mean absolute relative difference between Dexcom G6 and YSI glucose >10mmol/L
- MARD for G6 and YSI 24hr pre [ Time Frame: 24 hours ]Mean absolute relative difference between Dexcom G6 and YSI glucose during 24 hours prior to heamodialysis
- MARD for Libre and YSI 24hr pre [ Time Frame: 24 hours ]Mean absolute relative difference between Libre and YSI glucose during 24 hours prior to heamodialysis
- MARD for Libre and YSI 24hr post [ Time Frame: 24 hours ]Mean absolute relative difference between Libre and YSI glucose during 24 hours after heamodialysis
- MARD for G6 and YSI 24hr post [ Time Frame: 24 hours ]Mean absolute relative difference between Dexcom G6 and YSI glucose during 24 hours after heamodialysis
- CEG analysis G6 and YSI [ Time Frame: 28 DAYS ]Clarke Error Grid analysis between Dexcom G6 and YSI glucose during haemodialysis
- CEG analysis Libre and YSI [ Time Frame: 28 DAYS ]Clarke Error Grid analysis between Libre and YSI glucose during haemodialysis
- Severe hypoglycaemia [ Time Frame: 28 days ]Episodes of severe hypoglycaemia
- DKA [ Time Frame: 28 days ]Diabetic Ketoacidosis
- Sensor failure [ Time Frame: 28 days ]Events of G6/libre sensor failure
- Missing glucose data [ Time Frame: 28 days ]Missing blood glucose data for G6/libre measured by number of missing data points

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Adults >18 years of age
- Diabetes, with insulin treatment for over 6 months or on sulphonylureas
- Chronic kidney disease requiring haemodialysis three times per week
Exclusion Criteria:
- Pregnant or planning pregnancy
- Breastfeeding
- Enrolled in other clinical trials
- Have active malignancy or under investigation for malignancy
- Severe visual impairment
- Reduced manual dexterity
- Unable to participate due to other factors, as assessed by the Chief Investigators

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03885362
Contact: Nick Oliver | 0207 594 2460 | nick.oliver@imperial.ac.uk |
United Kingdom | |
Imperial College London/NHS trust Renal Unit | Recruiting |
London, United Kingdom | |
Contact: Nick Oliver, FRCP 0207 594 2460 nick.oliver@imperial.ac.uk | |
Principal Investigator: Nick Oliver | |
Sub-Investigator: Tricia Tan | |
Sub-Investigator: Andrew Frankel | |
Sub-Investigator: Jo Reed |
Principal Investigator: | Nick Oliver | Imperial College London |
Responsible Party: | Imperial College London |
ClinicalTrials.gov Identifier: | NCT03885362 |
Other Study ID Numbers: |
18SM4938 |
First Posted: | March 21, 2019 Key Record Dates |
Last Update Posted: | October 22, 2020 |
Last Verified: | October 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Type 1 Diabetes Mellitus Chronic Kidney Diseases |
Kidney Diseases Renal Insufficiency, Chronic Diabetic Nephropathies Diabetes Mellitus Diabetes Mellitus, Type 1 Glucose Metabolism Disorders Metabolic Diseases |
Endocrine System Diseases Urologic Diseases Autoimmune Diseases Immune System Diseases Renal Insufficiency Diabetes Complications |