Continuous Glucose Monitoring Alerts, Accuracy, and Patient Outcomes in Adults With Inherited Metabolic Disorders

University Hospital Padova11 enrolled

Overview

The goal of this clinical trial is to learn if a continuous glucose monitor (CGM) with predictive alerts works better than a CGM with standard alerts to prevent low blood sugar (hypoglycemia) in adults with inherited metabolic disorders (IMDs), such as glycogen storage disorders (GSDs) and congenital hyperinsulinism (CH). The main questions it aims to answer are: Does a CGM with predictive alerts lower the time spent with low blood sugar compared to a CGM with standard alerts? Do participants feel better and behave differently when using a CGM with predictive alerts? How accurate are the two CGM devices in this group of people? Researchers will compare two CGM devices - Dexcom G7 (with predictive and standard alerts) and Dexcom ONE+ (with standard alerts only) - to see if predictive alerts help reduce low blood sugar episodes and improve quality of life. Participants will: Wear each CGM device for 30 days Have a 30-day break between the two devices Check blood sugar levels and record food intake Complete questionnaires about their experience with each device

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

NONE

Enrollment

Conditions

Glycogen Storage Disease Congenital Hyperinsulinism (CHI)

Interventions

Continuous glucose monitor with threshold and predictive alerts (Dexcom G7)DEVICE

The Dexcom G7 is a CE-marked continuous glucose monitoring (CGM) device worn for 30 days. It provides real-time interstitial glucose readings every 5 minutes. The device offers both threshold-based alerts, activated when glucose levels fall below or rise above pre-set values, and predictive alerts, activated when glucose levels are predicted to reach a threshold within 20 minutes. The low glucose alert threshold was set at 70 mg/dL for all participants.

Continuous glucose monitor with threshold-only alerts (Dexcom ONE+)DEVICE

The Dexcom ONE+ is a CE-marked continuous glucose monitoring (CGM) device worn for 30 days. It provides real-time interstitial glucose readings every 5 minutes. The device offers threshold-based alerts only, activated when glucose levels fall below or rise above pre-set values, without predictive alert functionality. The low glucose alert threshold was set at 70 mg/dL for all participants.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18 years or older * Genetic or biochemical diagnosis of Glycogen Storage Disease (GSD) or Congenital Hyperinsulinism (CH) * At least one clinical and biochemical follow-up at the hospital outpatient service within the last one or two years * Ability to sign informed consent and comply with study procedures Exclusion Criteria: * Inability to sign informed consent or comply with study procedures

Locations (1)

University Hospital of Padova

Padova, Padova, Italy

Outcomes

Primary Outcomes

Time Below Range (TBR)

Percentage of time spent with interstitial glucose levels below 70 mg/dL, as measured by continuous glucose monitoring (CGM). TBR is reported at two thresholds: TBR1 (54-69 mg/dL) and TBR2 (\<54 mg/dL), both expressed as percentage of monitoring time (%), over 30 days for each device. Unit of Measure: % of monitoring time

Time frame: 30 days per device (total study duration: approximately 90 days including washout period)

Secondary Outcomes

Time in Range (TIR)

Percentage of time spent with interstitial glucose levels within the target range of 70-140 mg/dL, as measured by CGM over 30 days for each device. Expressed as percentage of monitoring time (%). Unit of Measure: % of monitoring time

Time frame: Time Frame: 30 days per device

Time Above Range (TAR)

Percentage of time spent with interstitial glucose levels above 140 mg/dL, as measured by CGM over 30 days for each device. Expressed as percentage of monitoring time (%). Unit of Measure: % of monitoring time

Time frame: Time Frame: 30 days per device

Mean Glucose Level

Mean interstitial glucose levels calculated over 24 hours and during nighttime (00:00-07:00), as measured by CGM over 30 days for each device. Unit of Measure: mg/dL

Time frame: Time Frame: 30 days per device

Sensor Accuracy - median absolute relative difference (MARD)

Accuracy of CGM readings compared to capillary blood glucose reference values (Accu-Check Instant, Roche), expressed as Median Absolute Relative Difference (MARD). Capillary and CGM values matched within a ±5-minute time window. Unit of Measure: %

Time frame: 30 days per device

Dietary Intake Assessment

Total daily energy intake measured during each device wear period Unit of Measure: kcal/day Total daily macronutrient intake measured during each device wear period Unit of Measure: grams/day Daily uncooked cornstarch intake measured during each device wear period Unit of Measure: grams/day All dietary intakes were assessed by 7-day food diary analyzed with Metadieta® software (Meteda Srl, Italy), completed during CGM monitoring and reviewed by an experienced metabolic dietitian.

Time frame: 7 days per device

Hypoglycemia Fear and Protective Behaviors Assessment

Assessed using the Hypoglycemia Fear Survey (HFS), comprising two subscales: Worry (HFS-W) and Behavior (HFS-B). Each item scored 0-4; total range 0-132; higher scores indicate greater fear of hypoglycemia and more behaviors engaged to avoid hypoglycemic episodes. Unit of Measure: Score (0-132)

Time frame: baseline and after 30 days per device

Hypoglycemia Awareness Assessment

Assessed using the Clarke Hypoglycemia Awareness Questionnaire (CHAQ), comprising 8 items on hypoglycemia awareness and recognition. Range 0-7; scores ≥4 indicate impaired awareness of hypoglycemia; higher scores indicate worse hypoglycemia awareness. Unit of Measure: Score (0-7)

Time frame: baseline and after 30 days per device

Sleep Quality Assessment

assessed using the Pittsburgh Sleep Quality Index (PSQI), a self-report questionnaire assessing sleep quality and disturbances over the previous month. Global score ranges from 0 to 21; scores \>5 indicate poor sleep quality; higher scores indicate worse sleep quality. Unit of Measure: Score (0-21)

Time frame: Baseline and after 30 days per device

Health-Related Quality of Life Assessment

Assessed using the 12-Item Short Form Health Survey (SF-12), yielding Physical Component Summary (PCS) and Mental Component Summary (MCS) standardized scores. Higher scores indicate better quality of life. Unit of Measure: Standardized score for Italian population

Time frame: Baseline and after 30 days per device

Body Mass Index (BMI)

Height measured at baseline; weight measured at the start and end of each CGM period using a calibrated mechanical scale (Seca 700). BMI calculated as weight (kg)/height² (m²), interpreted according to WHO classification: \<18.5 underweight; 18.5-25 healthy weight; 25-30 overweight; \>30 obesity. Unit of Measure: kg/m²

Time frame: Baseline and after 30 days per device

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.