Accuracy of Two CGM Systems Tested Simultaneously in Ambulatory Patients With Type 1 Diabetes
Accuracy of Two CGM Systems Tested Simultaneously in Ambulatory Patients With Type 1 Diabetes
Continuous glucose monitoring (CGM) is a tool used in the treatment of patients with type 1
 diabetes. A continuous glucose monitor (CGM) is a subcutaneous tissue sensor, which provides
 a tissue fluid glucose measurement every 1 to 5 minutes. Since CGM measure the glucose level
 by a sensor in subcutaneous tissue, there is uncertainty in the estimation of blood glucose
 levels. The accuracy of a certain CGM system can be assessed by comparing the glucose levels
 estimated by CGM with measured glucose levels in plasma. In the current study, we will
 compare the accuracy of the 2 CGM systems available on the market for clinical use in
 patients with type 1 diabetes. The aim of the current study is to evaluate effectiveness,
 safety and treatment satisfaction with 2 different CGM systems among adult type 1 diabetic
 patients.
Each study patient will have both subcutaneous tissue CGM sensors inserted. Each sensor will
 produce a maximum of 1,440 tissue fluid glucose measurements per 24 hours and 8,460
 measurements during the 6 days in study. The plan is to study 36 to 50 ambulatory patients
 during the hole study period. The two CGM data sets (DexCom4G and Medtronic Enlite) will be
 compared to each other and the time-matched reference blood glucose measurements.

 The HemoCue Analyser- venous blood and finger-stick blood in cuvette, will be used to measure
 the concentration of glucose.

 Each ambulatory patient will sample capillary blood and measure the concentration of glucose
 6 to 10 times per day for max 6 days. The concentration of finger-stick capillary blood
 glucose will be measured using the HemoCue meter in their daily living and additionally a
 HemoCue Analyser at research visits using a lancet. Each patient will be admitted to the
 clinical research unit (CRU) for 7 measurements of venous samples at two occasions: on day
 1-3 and 4-6 of the study with an interval of at least 15 minutes. An intravenous catheter
 will be inserted to facilitate blood sample acquisition each of these days of study. Three
 capillary finger-stick blood will be sampled at these 2 occasions, 1 at the first venous
 measurement (one day of days 1-3) and one at the last venous sample (one day of days 4-6).

 Blood sample acquisition and handling will be standardized to minimize pre-analytical error.

 The sensor insertion sites will be observed to detect bleeding, inflammation and infection of
 the skin or subcutaneous tissue. Insertion sites will be photographed if any abnormal
 findings exist at the end of the study for the individual patient.

 The subjects will record self monitoring of blood glucose (SMBG), meal, and activity data in
 a written diary.
Inclusion Criteria:

 1. Type 1 diabetes

 2. Adult patients, age 18 or older and <75 years.

 3. Written Informed Consent

 Exclusion Criteria:

 1. Pregnancy

 2. Patients with severe cognitive dysfunction or other disease which makes CGM use
 difficult.

 3. Patients requiring continuous use of paracetamol. Paracetamol must not have been used

 the week before the study and shall not be used during the duration because it
 disturbs the

 interpretation of blood glucose levels estimated by the DexCom4G. However, other pain

 killers can be used throughout the study period.

 4. Current CGM use

 5. History of allergic reaction to any of the CGMS materials

 or adhesives in contact with the skin.

 6. History of allergic reaction to chlorhexidine or alcohol

 anti-septic solution.

 7. Abnormal skin at the anticipated glucose sensor

 attachment sites (excessive hair, burn, inflammation,

 infection, rash, and/or tattoo).