Continuous Glucose Monitoring in Hospitalized Patients With Diabetes Mellitus

CGM Use in Hospitalized Patients With Diabetes Mellitus

The purpose of this study is to determine if patient's own Continuous Glucose Monitor (CGMs) worn in the non-ICU hospital setting have adequate accuracy for blood glucose monitoring when compared to point-of-care (POC) capillary glucose measurement, and to determine if alerts given by CGMs worn in the non-ICU hospital would prevent episodes of hyperglycemia and hypoglycemia.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus
• Intervention / Treatment: Device: Continuous Glucose Monitor (CGM)

Detailed Description

All patients admitted to the hospital in inpatient or observation status and having a Continuous Glucose Monitor (CGMs) attached will be screened and identified by providers and nurses. An order will be placed by providers to continue patient's home CGM use in the hospital. "CGM patient agreement" describing the hospital policy for use of CGMs will be provided to the patient for signature. Patients will be encouraged to continue to wear their CGMs in the hospital unless their presence interferes with patients' medical care. CGM presence will be recorded by nursing in patient chart under LDA (lines, drains, airway) section. Patients will be approached by the research staff and will be offered enrollment in the study. A research consent will be reviewed with patients and will be provided for signature. Patients will be asked to continue to use their home CGMs in the hospital. If CGM sensor will reach the end of life, patients have the option to place a new sensor and to follow manufacturer recommendations for calibration and setting. Patients are responsible to provide their own sensors, transmitters and readers during the hospitalization period. If it is determined that the current sensor will interfere with hospital medical and surgical care (MRI testing, procedure at the site), patients will be asked to remove the CGM sensor and transmitter. Patients will have the option to replace the sensor after the procedure if they so desire.

Patients will continue to monitor their glucose level via CGM. For flash sensors, patients will be asked to scan their sensor at least every 8 and as needed. CGMs that require calibration will be calibrated by the patients using hospital glucometer readings. .

Patients alerted by their CGM about low glucose levels or fast downward or upward trending will have to notify their nursing staff. A POC blood glucose check will be done by nursing staff to confirm the alert or the trend. Treatment decisions will be made based on POC readings.

During hospitalization patients will continue to have their blood glucose checked with POC glucometers per hospital policy.

Treatment of diabetes and the associated complications, dosing of insulin, change from PO to insulin treatment and back to PO medications during hospitalization or at discharge will be done by the admitting team with help from the inpatient Endocrinology Consultation Service.

Decisions about insulin dosing or other diabetes treatments will be made based on hospital glucometer readings, and not based on CGM readings alone.

Patients will be asked to give the research team "provider access" to their cloud CGM software, or to allow the team to download their CGM data prior to discharge if their reading devices do not automatically synchronize with the cloud software.

CGM data will be compared with POC glucometer readings obtained in the hospital at approximately the same time. Different patient variables (demographics, comorbidities, labs and vitals, administered medications) will be collected from electronic health record and will be evaluated to determine if they interfere with CGM readings. The accuracy of CGM for glucose measurement in the hospital will be calculated.

• Study Type: Interventional
• Enrollment (Actual): 142
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic in Florida

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients with Type 1 or 2 Diabetes Mellitus,
• Patients 18 years of age or older,
• Patients admitted under medical or surgical services.
• Patients treated with diet alone, insulin (SQ, insulin pump) or oral hypoglycemic medications.
• Have their own Continuous Glucose Monitoring (CGM) monitor present on admission or able to be placed after admission.

Exclusion Criteria:

• Individuals under 18 years of age.
• COVID-19 infection.
• Infection of the skin at the CGM site requiring removal of the sensor.
• Patients with altered Mental Status.
• Patients unable to scan their flash CGMs at least every 8 hours.
• Inability to provide written consent.
• Hospitalized for less than 24 hours.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CGM Patients; Patients with diabetes mellitus admitted to the hospital and using a CGM will be encouraged to continue to use these devices in inpatient setting. The device alarms of high or low glucose levels will be communicated to the nursing staff.	Device: Continuous Glucose Monitor (CGM); CGM data will be downloaded prior to discharge and it will be compared with hospital glucometer readings taken at the same time.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Continuous Glucose Monitors (CGM) Accuracy - Mean Absolute Relative Difference (MARD)	The absolute relative difference (ARD) was defined as the absolute difference between control - point of care (POC) glucose reading and the corresponding CGM reading divided by POC glucose reading and expressed as percentage. ARD was calculated as mean absolute relative difference (MARD) with standard deviation. MARD was calculated between matched pairs of POC (point of care) glucose readings and the closest CGM reading. MARD was summarized as mean (standard deviation) or median (range) for glucose readings <70 mg/dl, 70-180 mg/dL, >180 mg/dl, 181-250mg/dl, >250 mg/dl respectively.	From date of enrollment and until discharge from the hospital up to 30 days.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
CGM Recorded Hypoglycemia Episodes	The incidence of hypoglycemic episodes	From date of enrollment and until discharge from the hospital up to 30 days.
CGM Recorded Duration of Hypoglycemic Episodes	CGM recorded duration of hypoglycemic episodes	From date of enrollment and until discharge from the hospital up to 30 days.
CGM Recorded Hyperglycemic Episodes	The incidence of hyperglycemic episodes	From date of enrollment and until discharge from the hospital up to 30 days.
CGM Recorded Duration of Hyperglycemic Episodes	The duration of hyperglycemic episodes	From date of enrollment and until discharge from the hospital up to 30 days.
Variation in Mean Absolute Relative Difference (MARD) in Relation to Pharmacological and Physiological Parameters	The correlation between MARD point of care (POC) and Creatinine, Glomerular Filtration Rate (GFR), Bicarbonate, Hemoglobin (Hb), Mean Arterial Pressure (MAP), and Peripheral Oxygen Saturation (SpO2). The Spearman's rank correlation method was used to calculate the correlation coefficient.	From date of enrollment and until discharge from the hospital up to 30 days.
In Hospital Mortality	Mortality during index hospitalization	From date of enrollment and until discharge from the hospital up to 30 days.
Hospitalization Length of Stay	Duration of hospital stay in hours	From date of enrollment and until discharge from the hospital up to 30 days.
Mortality Rate at 30 Days	Mortality rate at 30 days post discharge from the hospital	From date of enrollment up to 60 days.
Number of Re-hospitalization Events at the Same Institution Within 30 Days From the Discharge Date of the Preceding Admission.	Number of re-hospitalization events that occurred at the same institution within 30 days from the discharge date of the preceding admission.	From date of enrollment up to 60 days.

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Investigators: Principal Investigator: Adrian Dumitrascu, MD, Mayo Clinic

Publications and helpful links

Helpful Links

• Mayo Clinic Clinical Trials

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2021
• Primary Completion (Actual): November 10, 2023
• Study Completion (Actual): November 10, 2023

Study Registration Dates

• First Submitted: November 6, 2020
• First Submitted That Met QC Criteria: November 28, 2020
• First Posted (Actual): December 4, 2020

Study Record Updates

• Last Update Posted (Actual): July 31, 2025
• Last Update Submitted That Met QC Criteria: July 11, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: CGM, Continuous Glucose Monitor
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus
• Other Study ID Numbers: 20-008826

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No