Clinical trial NCT04452396: CGM (Continuous Glucose Monitoring) Use in Diagnosis of Spontaneous and Reactive Hypoglycaemia
Official title: Continuous Glucose Monitoring: An Evaluation of Impact on Improving the Efficiency of Diagnostic Processes and Enhancing Patient Safety in the Management of Reactive and Spontaneous Hypoglycaemia
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: NA
Conditions: Hypoglycemia, Reactive
Hypoglycaemia Night
Hypoglycemia Non-Diabetic
Hypoglycemia Unawareness
Insulinoma
Insulinoma; Malignant, Pancreas
Insulin Hypoglycemia
Insulin Resistance
Spontaneous Hypoglycemia
Neuro Endocrine Tumours
Keywords: hypoglycaemia
insulinoma
Lead sponsor: Barts & The London NHS Trust
Sponsor class: OTHER
First posted: 2020-06-30
Enrollment: 7
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: 2 phases to study. Patients can enter at start of either phase and start phase 2 at the end of phase 1.

Phase 1 - CGM monitoring of people with suspected spontaneous/reactive hypoglycaemia phase 2 - CGM monitoring of patients with medically managed spontaneous/reactive hypoglycaemia
Primary purpose: DIAGNOSTIC

Brief summary: Use of CGM to determine diagnosis in possible spontaneous or reactive hypoglycaemia.

Use of CGM to aid treatment optimisation in spontaneous or reactive hypoglycaemia

Detailed description: The human body's blood sugar levels are tightly controlled by the hormone insulin, produced by the pancreas. If the pancreas produces too much insulin, then the blood sugar will fall to low levels (hypoglycaemia). Insulin overproduction can happen as a result of the body misreading a change in blood sugar levels after eating (such as after obesity surgery) or through tumours of the pancreas which overproduce insulin (insulinomas).

Hypoglycaemia can cause subtle symptoms such as tiredness, poor concentration, or dizziness and if untreated more severe symptoms including fits, coma and death. Low blood sugars can go unnoticed at night and if levels fall frequently, people can lose their ability to notice subtle symptoms.

People suspected of having hypoglycaemia require a series of investigations to try and reproduce a low blood sugar under controlled conditions. This often requires an admission to hospital for a few days and multiple finger pricks to test the blood sugar - which patients often find painful. If low blood sugars caused by too much insulin are confirmed then medical treatment is started in the first instance, with surgery possibly following later. The only way to check whether these medications are working is by home fingerprick glucose measurements. If people have low sugars at night or have lost their ability to notice symptoms of low blood sugar, it is very difficult to be sure that the medical treatment is working.

The investigators plan to use continuous glucose monitoring probes to measure patient's blood sugar prior to and during admission for formal investigation for hypoglycaemia (alongside conventional fingerprick and blood testing). This might allow us to exclude hypoglycaemia as a cause of their symptoms, avoiding lengthy admissions.

The investigators will also use this technology (alongside fingerprick testing) to test how well medical treatment is working in patients with proven hypoglycaemia.

Eligibility criteria: Inclusion Criteria:

* phase 1 - under investigation for possible/probable hypoglycaemia
* phase 2 - on medical therapy for established hypoglycaemia
* Must be Able and willing to give informed consent. No vulnerable adults will be included.
* Must be Aged \>18 years

Can be;

* Any ethnicity
* Any socio economic group
* Either conventional gender, or non-binary.

Exclusion Criteria:

* Must not be unwilling or unable to give consent
* Must not be unable to speak sufficient English to give consent and understand study requirements
* Must not be Aged\<18 or \>90 years
* Must not be lack capacity to consent
* Must not have an underlying hepatic condition
* Must not have a current excessive alcohol consumption (men regularly consuming \>50 units/week, women \>35 units/week)
* Must not have Diabetes Mellitus
* Must not be currently using Diabetic medication or insulin
* Must not be currently pregnant
* Must not be on haemo or peritoneal dialysis

Primary outcomes:
measure: study arm 1 - diagnosing hypoglycaemic episodes using Continuous Glucose Monitoring of interstitial fluid as a proxy marker of blood glucose
timeFrame: up to 5 days prior to admission for hypoglycaemia investigations
measure: study arm 1 - diagnosing hypoglycaemic episodes (glucose measurement <4mmol/L) using Continuous Glucose Monitoring of interstitial fluid as a proxy marker of blood glucose
timeFrame: up to 5 days in hospital during investigations for hypoglycaemia
measure: study arm 2 - using Continuous Glucose Monitoring of interstitial fluid as a proxy marker of blood glucose to optimise hypoglycaemia treatment in patients with an established diagnosis of spontaneous or reactive hypoglycaemia
timeFrame: up to 30 days
Secondary outcomes:
measure: assessing concordance between CGMS and lab/finger prick glucose testing
timeFrame: up to 10 days (study arm 1) or up to 30 days (study arm 2)
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: St Bartholomew's Hospital, dept of endocrinology
Study officials:
References: