Influence of Continuous Glucose Monitoring on Quality of Life in People With Type 2 Diabetes Mellitus (Glucocavi)

June 27, 2025 updated by: Sergi Rodríguez Soler, Fundacio d'Investigacio en Atencio Primaria Jordi Gol i Gurina

Background: Diabetes Mellitus (DM) is a chronic disease that affects millions of people worldwide. More than 95% of cases are type 2 diabetes mellitus (T2DM). In recent years, diabetes management has evolved with the introduction of continuous glucose monitoring (CGM) devices. These devices implanted under the skin allow continuous measurement of glucose levels monitoring glucose trends and the rate at which glucose level rise and fall without the need for capillary glycaemias test. While studies demostrate the effectiveness of CGM devices in controlling glucose levels in adults with T2DM, there is no evidence related to quality of life in this patients.

Hypothesis: The use of CGM in people with T2DM improves their quality of life, reduces distress about the disease, reduces fear of hypoglycaemia, increases detection of hypoglycaemia, and improves metabolic control.

Objectives: To assess quality of life, diabetes distress, fear of hypoglycaemia, detection of hypoglycaemia, and metabolic control in people with T2DM before and after the use of CGM sensors.

Methodology: Prospective observational pre-post unblinded study. Adults with type 2 diabetes using a CGM device in the primary care setting will be followed for 12 months. They will be asked to complete 5 questionnaires at baseline, and 4 questionnaires at 3, 6 and 12 months. No other activity that differs from usual clinical practice will be performed.

Data analysis: a descriptive analysis of the main study variables will be carried out and the differences in the data before and after the intervention will be analysed using the chi-square test for qualitative variables, and the Student's t-test for quantitative variables. Statistical significance will be accepted at a p-value < 0.05.

Applicability and relevance: The results of the study will provide information on whether CGM devices improve quality of life and glycaemic control in people with type 2 diabetes. With these results it will be possible to assess whether it is beneficial to extend funding for CGM devices to more of the population than is currently the case.

Study Overview

Detailed Description

Study development: The recruitment period runs from September 2024 to February 2025. Participants will be recruited by health professionals (nurse or doctor) CGM referents from each of the 20 primary care centres in the Camp de Tarragona health region. Sampling will be by convenience, all persons who meet the inclusion criteria and none of the exclusion criteria will be offered to participate in the study. Participants must sign an informed consent and their data will be coded.

Participants will be asked to fill in 5 questionnaires at the beginning of the study:

  • Sociodemographic questionnaire created ad hoc to know the profile of the patients.
  • EsDQOL questionnaire that assesses the quality of life related to diabetes.
  • DDS17 questionnaire that assesses diabetes-related distress.
  • EsHFS questionnaire that assesses fear of hypoglycaemia.
  • Clarke Test that assesses the detection of hypoglycaemia.

The EsDQOL, DDS17, EsHFS and Clarke Test questionnaires must be repeated at 3, 6 and 12 months after the start of the study. Participants will be called to their primary care centre of reference to fill in the questionnaires themselves and these will be kept on paper at the centre until data analysis.

To assess metabolic control, the data provided by the CGM sensor will be used and the results of the AGP (Ambulatory Glucose Profile) report of the first 2 weeks will be compared with the data at 3, 6 and 12 months. No analytical tests or capillary blood glucose measurements will be requested.

Data analysis: A descriptive analysis of the main study variables will be performed using percentages for qualitative variables and mean and standard deviation for quantitative variables. To analyse the differences in the data before and after the intervention, chi-square tests will be used for qualitative variables and the Student's t-test for quantitative variables. Statistical significance will be accepted with a p-value <0.05. Data will be analysed using SPSS statistical software version 23 or later.

Sample calculation: Accepting an alpha risk of 0.05 and a statistical power greater than 0.8 in a bilateral contrast, 55 subjects are required to detect as statistically significant a difference equal to or greater than 9 units in the EsDQOL questionnaire (main study variable). A common standard deviation of 23.65 is estimated. A loss to follow-up rate of 0% is estimated. [GRANMO sample size calculator v7.10 available at Calculator (laalamedilla.org)].

Study Type

Observational

Enrollment (Estimated)

55

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Barcelona, Spain, 08007
        • IDIAP Jordi Gol

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population is adults in an industrialised country with a diagnosis of type 2 diabetes with intensive insulin regimen who will start using a CGM sensor. Participants will be recruited from primary care centres in the Camp de Tarragona health region following inclusion and exclusion criteria. Depending on the location of the primary care centre, the population may be from an urban, semi-urban, or rural setting.

Description

Inclusion Criteria:

  • Treatment with intensive insulin therapy (basal bolus regimen with 3 or more daily doses of insulin).
  • Perform 6 or more daily capillary glycaemia determinations.
  • Be willing to use a CGM device for at least 70% of the time.
  • Undergo training on the use of the CGM device by the centre's CGM referent.
  • Agree to participate in the study.

Exclusion Criteria:

  • Cognitive impairment measured by Pfeiffer test with a score of 3 or more errors.
  • Previous use of a CGM device.
  • Pregnancy.
  • Being institutionalised.
  • Having participated in another research study related to diabetes mellitus within the last year.
  • Not having proper handling of the CGM device: inability to download glycaemic control data, inability to keep the sensor attached to the skin, not understanding how it works, etc.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Type 2 diabetes and continuous glucose monitoring Tarragona
People with type 2 diabetes and intensive insulin therapy who are using a continuous glucose monitoring sensor for the first time in the Camp de Tarragona health region.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference between pre and post "diabetes-related quality of life (EsDQOL)" questionnaire.
Time Frame: 0, 3, 6 and 12 months
A validated scale is used to measure diabetes-related quality of life. It consists of 43 questions with answers on a Likert scale from 1 to 5. The higher the score, the worse the quality of life.
0, 3, 6 and 12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference between pre and post "diabetes-related distress scale (DDS17)".
Time Frame: 0, 3, 6 and 12 months
A validated scale is used to measure diabetes-related distress. It consists of 17 questions with answers on a Likert scale from 1 to 6. An average score < 2 points is considered normal, moderate distress a score between 2.0 and 2.9 points, and high distress a score equal to or higher than 3.
0, 3, 6 and 12 months
Difference between pre and post "hypoglycaemia fear test (EsHFS)".
Time Frame: 0, 3, 6 and 12 months
A validated scale is used to measure the hypoglycaemia fear. It consists of 24 questions with answers on a Likert scale from 1 to 5. The higher the score, the greater the fear of hypoglycaemia.
0, 3, 6 and 12 months
Difference between pre and post "undetected hypoglycemia test (Test de Clarke)".
Time Frame: 0, 3, 6 and 12 months
A validated test that assesses the patient's ability to detect hypoglycaemia. Each response is classified as normal or abnormal. If the sum total of abnormal responses is ≥4, the patient has an abnormal perception of hypoglycaemia, 3 abnormal responses is considered undetermined, and 2 or less is considered normal perception.
0, 3, 6 and 12 months
Difference between pre and post metabolic control.
Time Frame: 2 weeks, 3 months, 6 months, 12 months.
The CGM sensor provides several metabolic control values: % time glucose in range (70-180mg/dl), % time between 70mg/dl and 54mg/dl, % time below 54mg/dl, % time between 180mg/dl and 250mg/dl, % time above 250mg/dl, average glucose, glucose management indicator (GMI), and glucose variability (%CV). Data from the patient's first AGP report 2 weeks after starting to use the CGM sensor will be compared with data at 3, 6 and 12 months.
2 weeks, 3 months, 6 months, 12 months.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Sergi Rodríguez-Soler, Nurse, Institut Català de la Salut

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 4, 2024

Primary Completion (Estimated)

May 31, 2026

Study Completion (Estimated)

May 31, 2026

Study Registration Dates

First Submitted

November 29, 2024

First Submitted That Met QC Criteria

December 3, 2024

First Posted (Actual)

December 4, 2024

Study Record Updates

Last Update Posted (Actual)

July 2, 2025

Last Update Submitted That Met QC Criteria

June 27, 2025

Last Verified

June 1, 2025

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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