Sympathetic Nerve Activity During Hypoglycemia and Exercise

June 9, 2015 updated by: Steve Davis, Vanderbilt University
The purpose of this study is to determine if either hypoglycemia or exercise cause differential responses in muscle and skin sympathetic nerve activity.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The body has defensive responses to correct low blood sugar (hypoglycemia). A vital component of this response is release of glucagon and activation of the sympathetic nervous system, which provides the means for raising blood glucose levels towards normal. We can measure circulating hormones indicating the level of these responses, but additionally, sympathetic nervous system responses can be measured directly. We can measure the sympathetic nerve activity that controls blood flow to muscles (MSNA) and blood flow and sweating to skin (SSNA). The purpose of this study is to determine if either hypoglycemia or exercise cause differential responses in muscle and skin sympathetic nerve activity. We would also like to determine what the sympathetic response is to cycling exercise with insulin and normal blood sugar. Therefore, we would like to test the sympathetic responses to insulin with normal blood glucose, hypoglycemia, and during exercise bouts and normal blood glucose, with or without insulin.

Study Type

Interventional

Enrollment (Actual)

36

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Tennessee
      • Nashville, Tennessee, United States, 37232
        • Vanderbilt University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 36 Healthy male and female subjects (18 males and 18 females) aged 18-40 yr
  • All potential volunteers will have routine blood test to screen for hepatic, renal, and hematological abnormalities
  • Body mass index ≤30kg · m-2
  • Normal bedside autonomic function
  • Female volunteers of childbearing potential will undergo HCG pregnancy test at screening and again on the study day.

Exclusion Criteria:

  • Pregnant women
  • Subjects unable to give voluntary informed consent
  • Subjects on anticoagulant drugs or anemic
  • Subjects with a recent medical illness
  • Subjects with a history of hypertension, heart disease or cerebrovascular disease
  • Subjects with known liver or kidney disease
  • Subjects with recent weight loss or consuming a low carbohydrate diet

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 1
Hyperinsulinemic euglycemic or hypoglycemic clamp with Muscle and skin sympathetic nerve activity recording in arm and/or leg
Procedure: Hyperinsulinemic glucose clamp procedures
2 hours of either euglycemic or hypoglycemic glucose clamping
Experimental: 2
Exercise with insulin or no insulin infused with muscle and skin sympathetic nerve activity measurements
Procedure: moderate exercise
90 minutes of moderate exercise with either hyperinsulinemia or euinsulinemia

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Muscle sympathetic nerve activity
Time Frame: 2 hours
2 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vanderbilt University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2002

Primary Completion (Actual)

July 1, 2008

Study Completion (Actual)

July 1, 2008

Study Registration Dates

First Submitted

January 29, 2008

First Submitted That Met QC Criteria

January 29, 2008

First Posted (Estimate)

February 6, 2008

Study Record Updates

Last Update Posted (Estimate)

June 10, 2015

Last Update Submitted That Met QC Criteria

June 9, 2015

Last Verified

June 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB#020777-SNA during hypo/ex

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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