Inpatient Use of Personal Continuous Glucose Monitor (CGM) to Improve Diabetes Mellitus Control

This study will be a single center, randomized, unblinded, prospective, crossover, 2 arm, pilot study. The study will compare the glucose control in hospitalized patients with diabetes mellitus on insulin therapy and wearing a personal CGM when the CGM data will be continuously accessed versus glucose control for hospitalized patients not having the CGM data continuously accessed and receiving inpatient standard of care for diabetes mellitus.

Population:

Adult patients with diagnosis of diabetes mellitus, receiving subcutaneous insulin therapy in the hospital or in the home hospital program - Advanced Care at Home Program (ACH) and wearing a personal real time CGM at the time of admission.

Eligible subjects will be identified and will be approached for enrollment in person by the research coordinators. After enrollment they will be randomized in 2 arms: intervention and control arms.

Both intervention and control arm subjects:

* Will have their 14-day outpatient CGM data obtained and presented to DM treating providers. * Will sign a Hospital CGM Use Agreement per hospital protocol. * Will agree to share CGM device data with Mayo Clinic Research Team and will accept the invitation to share this data. * Will continue to monitor their CGMs with their personal reader/phone and inform the nursing staff of any alarms. * Will be responsible for providing their own CGM supplies during hospitalization and inserting the new CGM sensor either after a sensor is removed or at the end of sensor life if this occurs before discharge from the hospital. * Will be responsible for keeping their reader/phone connected to cellular network and charged in order to retrieve information from CGM and transmit it to CGM manufacturer servers. * Will have their CGM sensors removed per manufacturer recommendations prior to MRI or surgery that involves diathermy. * Will have glucose checked with POC glucometer before meals and at bedtime or q4 hours while receiving subcutaneous insulin or every hour while receiving intravenous insulin as ordered by primary team. * If re-hospitalized after the initial hospitalization, they will be enrolled in the opposite study arm and will continue with intervention.

Control Arm subjects:

* Will continue with current hospital standard of care for IP glucose monitoring and insulin adjustment via POC glucometers. * Will have their aggregated CGM data for the hospitalization downloaded and analyzed after their discharge from the hospital.

Intervention Arm subjects:

* Will continue to use POC glucometer checks prior to meals per hospital orders. * Will send a link for active follow of RT-CGM data with hospitalist treatment team and DM inpatient APPs. * Their aggregated CGM reading per day will be reviewed daily by the HIM treating team or DM inpatient APPs and adjustments to insulin therapy will be made with the aim of diminishing future hypoglycemia and hyperglycemia events. Immediate insulin dosing adjustments will be made also by using POC glucometer readings. * During working hours (8am to 5pm) if a low or an impending low glucose alert will be received by the devices followed by Endocrinology APPs, ACH or HIM providers, patient RN will be notified to follow the hospital hypoglycemia treatment and prevention protocol (see attached). High glucose alerts will be used by Endocrinology APPs, ACH or HIM providers to make adjustments to insulin regimen. * On the monitoring devices present with Endocrinology APPs and HIM providers alerts will be set at 90 mg/dl for hypoglycemia and at 350 mg/dl for hyperglycemia. This will allow time for preventative actions to avoid hypoglycemia or severe hyperglycemia. * Prior to any treatment using medication to address CGM values of hypoglycemia and hyperglycemia, blood glucose confirmation with a POC glucometer will be made and it will be recorded in electronic medical record.

• Difference in Time Below Range <54 mg/dl and Time Below Range <70 mg/dl between subjects in intervention and control cohorts [Time frame: From admission date to discharge date up to 8 weeks.]
• Difference in Time Above Rance >180 mg/dl and Time Above Rance >250 mg/dl between subjects in intervention and control cohorts. [Time frame: From admission date to discharge date up to 8 weeks.]
• Measure subjects perceived satisfaction with CGM inpatient monitoring [Time frame: At the time of discharge date assessed up to 8 weeks.]