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Completed

NCT Number: NCT05189938

HbA1c Variation Study

To evaluate the relationship between glycated hemoglobin (HbA1c) and average glucose levels using continuous glucose monitoring.

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Key information

Age range

4 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

University Hospital Birmingham, Birmingham, United Kingdom

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About this study

This is a non-pivotal , non-randomized, single-arm, multi-center, prospective, non-significant risk study to evaluate the relationship between glycated hemoglobin (HbA1c) and average glucose levels. Up to approximately 600 subjects will be enrolled who will have fourteen (14) study visits over the course of approximately six (6) months. During each visit the subject will have blood samples drawn for documentation of their HbA1c level. Subjects will also be required to wear Professional FreeStyle Libre Flash Glucose Monitoring System(s) to record blood glucose levels through the duration of the study. During Visits 1 and 14, Venous sample for CBC, biochemistry, haemoglobinopathy screen, hematology, liver function and iron panels will be collected.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Subject must have type 1 or type 2 diabetes.
  • Subject is at least 4 years old.
  • Point-of-care (POC) HbA1C of 3.0%-15.5% (9 mmol/mol - 146 mmol/mol)
  • Subject must be able to read and understand English.
  • In the investigator's opinion, the subject must be able to follow the instructions provided to him/her by the study site and perform all study tasks as specified by the protocol.
  • Subject must be available to participate in all study visits.
  • Subject must be willing and able to provide written signed and dated informed consent.
  • Subjects age 4 - 17: Parent or guardian must be willing and able to provide written signed and dated informed consent.
  • Subjects age 11 - 17 Subject must be willing and able to provide written signed and dated informed assent.

Exclusion criteria

  • Subject is currently undergoing dialysis or planning to receive dialysis during the course of the study
  • History of blood transfusion in the last 3 months or planned blood transfusion during the course of the study.
  • Subject is currently planning to undergo a major medical intervention expected to significantly alter red cell life span, i.e. chemotherapy, major surgery requiring blood transfusions, etc.
  • Subject has known allergy to medical grade adhesive or isopropyl alcohol used to disinfect skin.
  • Subjects age 18 and older: Subject is known to be pregnant, attempting to conceive or is not willing and able to practice birth control during the study duration study (applicable to female subjects only). Subjects age 17 and younger: Subject is known to be pregnant at the time of study enrollment or is planning to become pregnant during the study (applicable to female subjects only).
  • Subject has extensive skin changes/diseases at the proposed application sites that could interfere with device placement or the accuracy of interstitial glucose measurements. Such conditions include, but are not limited to extensive psoriasis, recent burns or severe sunburn, extensive eczema, extensive scarring, dermatitis herpetiformis, skin lesions, redness, infection or edema.
  • Subject has a pacemaker or any other neurostimulators.
  • Subject has concomitant medical condition which, in the opinion of the investigator, could present a risk to the safety or welfare of the subject or study staff.
  • Subject is currently participating in another interventional clinical trial.
  • Subject is unsuitable for participation due to any other cause as determined by the Investigator.

Treatment and study plan

HBA1c data and glucose levels

Diagnostic Test

All subjects will wear the professional FreeStyle Libre Pro for glucose data and HbA1c data will be collected at different time points over the participation period.

Primary outcomes

  1. Establish a relationship between laboratory-derived HbA1c and average glucose levels

    Time frame: six (6) months

    This is an observational data collection study, where the goal is to gather data to establish the relationship between laboratory-derived HbA1c and average glucose levels.

Sponsors and collaborators

Lead sponsor

Abbott Diabetes Care

Industry

Registry information

Important dates

Study start
2021
Primary completion
2023
Study completion
2023
First posted
Jan 13, 2022
Registry last updated
May 25, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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