Hypoglycemia and Autonomic Nervous System Function

Study Overview
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Brief Summary
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The goals of this proposal are to determine the effects of hypoglycemia on the autonomic nervous system.

Official Title
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Hypoglycemia and Autonomic Nervous System Function

Conditions
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Hypoglycemia

Intervention / Treatment
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* Other: Hypoglycemic hyperinsulinemic clamp
* Other: Euglycemic hyperinsulinemic clamp


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Healthy volunteers Males and females age 18 to 50 years Exclusion Criteria Pregnancy Lactation Subjects who smoke or are on other forms of nicotine will be excluded Clinically evident coronary artery, cerebrovascular, or peripheral vascular disease, or presence of systemic illness that might affect autonomic function. Such illnesses include diabetes mellitus, congestive heart failure, hypertension, renal, pulmonary, hepatic disease, anemia, malignancies, untreated thyroid disease, and alcoholism. Current major depressive illness Any individuals on oral, injected, inhaled or topical corticosteroids within the last year or oral contraceptives within the past 3 months will be excluded. Use of medications other than thyroxine

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Euglycemic hyperinsulinemic clamp<br>participant undergoes a euglycemic hyperinsulinemic clamp | Other: Euglycemic hyperinsulinemic clamp<br> <br> |
| Active Comparator: Hypoglycemic hyperinsulinemic clamp<br>participant undergoes a hypoglycemic hyperinsulinemic clamp | Other: Hypoglycemic hyperinsulinemic clamp<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Baroreflex Sensitivity | The change in baroreflex sensitivity (milliseconds/mm Hg) is calculated as baroreflex sensitivity (milliseconds/mm Hg) on day 3 [assessed 16 hours after the clamp] minus baroreflex sensitivity (milliseconds/mm Hg) on day 1 [baseline assessment on the day prior to the clamp]). Change in baroreflex sensitivity in euglycemic clamp arm is compared to change in baroreflex sensitivity in hypoglycemic arm. | 16 hours after euglycemic and hypoglycemic clamps as compared to baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle Sympathetic Nerve Activity | Muscle sympathetic nerve activity (MSNA), at rest and immediately after nitroprusside, was measured on Day 3 about 16 hours after the euglycemic and hypoglycemic clamps. | 16 hours after euglycemic and hypoglycemic clamps | 
| Catecholamine Response to Lower-body Negative Pressure | Plasma norepinephrine response to lower body negative pressure (at the minus 40 mm Hg data point) on Day 3 about 16 to 20 hours after completion of the euglycemic or hypoglycemic clamp. | 16 hours after euglycemic and hypoglycemic clamps | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Autonomic Nervous System, baroreflex sensitivity, muscle sympathetic nerve activity, lower body negative pressure, Hypoglycemia