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Do Sulphonylureas Preserve Cortical Function During Hypoglycaemia?

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00472875
Recruitment Status : Unknown
Verified May 2007 by King's College Hospital NHS Trust.
Recruitment status was:  Recruiting
First Posted : May 14, 2007
Last Update Posted : May 14, 2007
Information provided by:
King's College Hospital NHS Trust

Brief Summary:
To see if using medication called sulphonylureas can help improve symptoms which patients rely on to recognise low blood glucose levels ( hypoglycaemia) and also to see if they can reduce the slowing down in brain function which occurs at hypoglycaemia.

Condition or disease Intervention/treatment Phase
Type 1 Diabetes Mellitus Drug: Glibenclamide Phase 4

Detailed Description:

Low blood glucose (hypoglycaemia) is the most common and important side effect of insulin treatment for diabetes. Most episodes are “mild” and lead to symptoms that alert the individual to raise their blood sugar level by consuming sugar or starch (carbohydrate). The body also responds to low blood sugars by producing hormones such as adrenaline and cortisol, which help to restore blood sugar levels to normal. As the brain relies on sugar for fuel, it does not function properly if blood sugar levels drop too low, resulting in confusion and in extreme cases reduced conscious levels.

Repeated hypoglycaemia can blunt the protective symptoms and hormonal responses to hypoglycaemia limiting patients’ ability to recognise and correct hypoglycaemia, putting them at high risk of even more hypoglycaemia (Heller and Cryer, 1991).

Sulphonylureas are tablets used to treat type 2 diabetes that work by stimulating the pancreas to make more insulin. They do this by closing pores called KATP channels which are found on the surface of many cells and control the rate of firing of cells. In the pancreas, closing them causes cells to fire and release insulin. However, in other tissues such as in the brain, these channels have a protective function and they open up during times of lack of fuel, such as lack of oxygen or sugar, preventing the cells from firing and putting them into a resting mode which reduces their energy requirement(Dunn-Meynell, Rawson and Levin 1998). However, if the brain cells responsible for generating symptoms are put into this resting mode, they may not produce symptoms, which may contribute to hypoglycaemia unawareness.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 10 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double
Primary Purpose: Treatment
Study Start Date : May 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Hypoglycemia
Drug Information available for: Glyburide

Primary Outcome Measures :
  1. Glucose threshold for development of symptoms and cognitive impairment due to hypoglycaemia [ Time Frame: 1 year ]

Secondary Outcome Measures :
  1. Improvement in counter regulatory hormone response to hypoglycaemia [ Time Frame: 1 year ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 18-75
  • Type 1 diabetes (WHO definition) of at least 5 years duration
  • History of impaired awareness of hypoglycaemia (capillary glucose readings < 3.5mmol/l without symptoms on > 3 occasions in the past 3 months (those with intact symptoms will be unlikely to show an improvement and would not really benefit from taking any medication intended just to increase symptoms)

Exclusion Criteria:

  • Pregnancy
  • Severe systemic illness
  • Active malignancy
  • Severe complications of diabetes such as severe visual impairment, severe renal impairment, severe symptomatic autonomic neuropathy
  • Untreated ischemic heart disease, recent stroke
  • Lactose intolerance ( the placebo will contain lactose)
  • Very poor diabetes control (HbA1c > 10%) Liver disease ( increase in ALT / AST > 3x ULN)
  • Chronic Kidney Disease stage 4 or 5 ( eGFR < 30ml/min)
  • Severe untreated thyroid or adrenal insufficiency ( must be treated and on stable doses for at least 6 weeks)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00472875

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Contact: Pratik Choudhary, MBBS, MRCP +44 203 299 9000 ext 2311
Contact: Stephanie A Amiel, MD, FRCP +44 203 299 9000 ext 4164

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United Kingdom
King's College Hospital NHS Foundation Trust Recruiting
London, United Kingdom, SE5 9RS
Sub-Investigator: David Hopkins, MBBS FRCP         
Sponsors and Collaborators
King's College Hospital NHS Trust
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Principal Investigator: Pratik Choudhary, MBBS MRCP King's College London

Layout table for additonal information Identifier: NCT00472875     History of Changes
Other Study ID Numbers: 07/Q0703/18
JDRF grant number 5-2007-478
First Posted: May 14, 2007    Key Record Dates
Last Update Posted: May 14, 2007
Last Verified: May 2007

Keywords provided by King's College Hospital NHS Trust:
type 1 diabetes mellitus

Additional relevant MeSH terms:
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Diabetes Mellitus, Type 1
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Autoimmune Diseases
Immune System Diseases
Hypoglycemic Agents
Physiological Effects of Drugs