Effect of Different Plasma Insulin Levels on the Accuracy of Continuous Subcutaneous Glucose Monitoring

NCT ID: NCT01714895

Last Updated: 2012-10-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 14 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2011-10-31
• Study Completion Date: 2012-10-31

Brief Summary

Achieving near-normoglycaemia has been established as the main objective for most patients with diabetes. However, it is well known that intensification of treatment is associated with an increase in the frequency of hypoglycemia, especially in the context of insulin therapy. The burden of hypoglycemia in terms of psychological implications, morbidity and even mortality, explains why it has been defined as the main limiting factor to achievement of good metabolic control.

Continuous subcutaneous glucose monitoring (CGM) devices have been claimed to be useful in hypoglycemia detection/prevention, allowing theoretically for safer intensification of therapy in diabetic patients. However, accuracy of CGM devices, especially in the hypoglycemic range, raises some concerns. In fact, commercially available CGM devices estimate plasma glucose from measurements in the interstitial fluid and not in plasma. However, the relationship between plasma and interstitial glucose is not fully understood, especially under dynamic conditions, and this may explain the poor CGM performance during rapid changes in blood glucose and hypoglycemia.

In this project, the relationship between plasma and interstitial glucose will be evaluated under conditions of normal glucose concentrations and hypoglycemia. Experiments will be performed to assess the role, if any, of different plasma insulin concentrations on the accuracy of CGM.

All the information obtained may be relevant to the improvement of the ability of CGM devices to detect hypoglycemia and hypoglycemic risk.

Conditions

Type 1 Diabetes; Continuous Glucose Monitoring; Hypoglycemia

Keywords

Interstitial glucose dynamics; Accuracy of continuous glucose monitoring under hypoglycemia; Glucose clamp

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: DOUBLE

Study Groups

High plasma insulin-Low plasma insulin

Seven out of the 14 subjects recruited in the study have been randomized to receive on the first study day a High insulin glucose clamp and on the second day a Low insulin glucose clamp (sequence 'AB')

Group Type: OTHER

High insulin eu-hypoglycemic clamp

Intervention Type: OTHER

Primed intravenous insulin infusion at a rate of 1mU/kg/min is given during the whole study duration. Glucose is infused at a variable rate to maintain plasma glucose concentrations 'clamped' at pre-specified levels. Plasma glucose levels will be the same in both study arms.

Low insulin eu-hypoglycemic clamp

Intervention Type: OTHER

Primed intravenous insulin infusion at a rate of 0.3mU/kg/min is given during the whole study duration. Glucose is infused at a variable rate to maintain plasma glucose concentrations 'clamped' at pre-specified levels. Plasma glucose levels will be the same in both study arms.

Low plasma insulin-High plasma insulin

Seven out of the 14 subjects recruited in the study have been randomized to receive on the first study day a Low insulin glucose clamp and on the second day a High insulin glucose clamp (sequence 'BA')

Group Type: OTHER

High insulin eu-hypoglycemic clamp

Intervention Type: OTHER

Primed intravenous insulin infusion at a rate of 1mU/kg/min is given during the whole study duration. Glucose is infused at a variable rate to maintain plasma glucose concentrations 'clamped' at pre-specified levels. Plasma glucose levels will be the same in both study arms.

Low insulin eu-hypoglycemic clamp

Intervention Type: OTHER

Primed intravenous insulin infusion at a rate of 0.3mU/kg/min is given during the whole study duration. Glucose is infused at a variable rate to maintain plasma glucose concentrations 'clamped' at pre-specified levels. Plasma glucose levels will be the same in both study arms.

Interventions

High insulin eu-hypoglycemic clamp

Primed intravenous insulin infusion at a rate of 1mU/kg/min is given during the whole study duration. Glucose is infused at a variable rate to maintain plasma glucose concentrations 'clamped' at pre-specified levels. Plasma glucose levels will be the same in both study arms.

Intervention Type: OTHER

Low insulin eu-hypoglycemic clamp

Primed intravenous insulin infusion at a rate of 0.3mU/kg/min is given during the whole study duration. Glucose is infused at a variable rate to maintain plasma glucose concentrations 'clamped' at pre-specified levels. Plasma glucose levels will be the same in both study arms.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Subjects with type 1 diabetes mellitus meeting all of the following criteria will be considered for admission to the study:

• Aged between 18 and 60 years
• Under CSII or MDI treatment for at least six months before Visit 1
• Body mass index of between 18 and 30 kg/m2
• HbA1c 6.0-8.5% at Visit 1
• Normal laboratory values, ECG, and vital signs unless the investigator considered an abnormality to be clinically irrelevant
• Women postmenopausal or using contraception judged by the investigator to be adequate (e.g., oral contraceptives, intra-uterine device or surgical treatment)

Exclusion Criteria

• Subjects meeting any of the following criteria will not be included in the study:

• Pregnancy and lactation
• History of hypersensitivity to the study medications or to drugs with similar chemical structures
• Confirmed hypoglycaemia unawareness
• Progressive fatal diseases
• History of drug or alcohol abuse
• History of positive HIV or hepatitis B or C test
• Impaired hepatic function, as shown by, but not limited to, SGPT or SGOT of more than twice the upper limit of the normal range at visit 1
• Impaired renal function, as shown by, but not limited to, serum creatinine > 1.5 mg/dL at visit 1
• Clinically relevant microvascular, cardiovascular, hepatic, neurologic, endocrine or other major systemic diseases other than T1DM which could hinder implementation of the clinical study protocol or interpretation of the study results
• Pre-planned surgery during the study
• Blood donation of more than 500 ml during the past three months for men, or during the past six months for women
• Mental condition rendering the subject unable to understand the nature, scope and possible consequences of the study
• Subject unlikely to comply with clinical study protocol, e.g., uncooperative attitude, inability to return for follow-up visits, or poor likelihood of completing the study
• Receipt of an experimental drug or use of an experimental device during the past 30 days.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Universitat Politècnica de València

OTHER

Sponsor Role: collaborator

Fundación para la Investigación del Hospital Clínico de Valencia

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Francisco Javier Ampudia-Blasco, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Hospital Clínico Universitario de Valencia - Fundación INCLIVA

Locations

Servicio de Endocrinología y Nutrición, Hospital Clínico Universitario de Valencia

Valencia, , Spain

Countries

Spain

References

Moscardo V, Bondia J, Ampudia-Blasco FJ, Fanelli CG, Lucidi P, Rossetti P. Plasma Insulin Levels and Hypoglycemia Affect Subcutaneous Interstitial Glucose Concentration. Diabetes Technol Ther. 2018 Apr;20(4):263-273. doi: 10.1089/dia.2017.0219. Epub 2018 Mar 12.

Reference Type: DERIVED

PMID: 29638161 (View on PubMed)

Other Identifiers

Spanish Ministry of Science

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

FP7-PEOPLE-2009-IEF #252085-2

Identifier Type: -

Identifier Source: org_study_id