Hypoglycemia and Autonomic Nervous System Function-B

NCT ID: NCT03429946

Last Updated: 2026-01-02

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE4

Total Enrollment

28 participants

Study Classification

INTERVENTIONAL

Study Start Date

2013-07-17

Study Completion Date

2025-11-25

Brief Summary

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This study tests the hypothesis that, compared to prior normal blood sugar, prior low blood sugar impairs cardiovascular autonomic function. The proposed studies will also test the hypothesis that the effects of prior low blood sugar on cardiovascular autonomic function are blocked by administration of a mineralocorticoid receptor antagonist.

Detailed Description

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This study involves three interventions, which are performed in random order. Each intervention involves a 3-day inpatient visit. There is a space of 1-3 months between interventions. The three interventions are: 1) placebo with a hyperinsulinemic euglycemic clamp, 2) spironolactone with a hyperinsulinemic hypoglycemic clamp, or 3) placebo with a hyperinsulinemic hypoglycemic clamp. Each 3-day inpatient visit includes the following. On Day 1, autonomic testing is performed. Autonomic testing includes assessment of Baroreflex Sensitivity (BRS). BRS is assessed using the Modified Oxford procedure, which involves sequential administration of nitroprusside and phenylephrine while measuring heart rate and beat to beat blood pressure with a finapress and assessing Muscle Sympathetic Nerve Activity (MSNA). MSNA is measured using microelectrodes placed near the peroneal nerve. On Day 2, hyperinsulinemic clamps are performed with pre-treatment with either placebo or spironolactone. Modified Oxford Procedures are performed prior to and during each clamp on Day 2. On Day 3, the autonomic testing performed on Day 1 is repeated..

Conditions

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Hypoglycemia Healthy

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Participants complete all 3 arms of the study in random order.
Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors
Investigator performing the clamp studies is only aware of the type of clamp - euglycemic versus hypoglycemic - but not aware of placebo versus spironolactone.

Study Groups

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Hypoglycemia and Spironolactone

Participants undergo two 120-minute hypoglycemic hyperinsulinemic clamp procedures (50 mg/dL) - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit. Participants receive two doses of 100 mg of spironolactone - one dose 12 hours and one dose 3 hours before the first clamp starts. Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Group Type ACTIVE_COMPARATOR

Spironolactone

Intervention Type DRUG

Participants will receive spironolactone 12 hours and 3 hours before the initiation of the hyperinsulinemic clamp treatment.

Hypoglycemic Hyperinsulinemic Clamp

Intervention Type OTHER

Participants undergo two 120-minute hypoglycemic (50 mg/dL) hyperinsulinemic clamps - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit. Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Hypoglycemia and Placebo

Participants undergo two 120-minute hypoglycemic hyperinsulinemic clamp procedures (50 mg/dL) - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit. Participants receive two doses of placebo - one dose 12 hours and one dose 3 hours before the first clamp starts. Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Group Type ACTIVE_COMPARATOR

Placebo

Intervention Type DRUG

Participants will receive placebo 12 hours and 3 hours before the initiation of the hyperinsulinemic clamp treatment.

Hypoglycemic Hyperinsulinemic Clamp

Intervention Type OTHER

Participants undergo two 120-minute hypoglycemic (50 mg/dL) hyperinsulinemic clamps - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit. Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Euglycemia and Placebo

Participants undergo two 120-minute euglycemic hyperinsulinemic clamp procedures (90 mg/dL) - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit. Participants receive two doses of placebo - one dose 12 hours and one dose 3 hours before the first clamp starts. Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type DRUG

Participants will receive placebo 12 hours and 3 hours before the initiation of the hyperinsulinemic clamp treatment.

Euglycemic Hyperinsulinemic Clamp

Intervention Type OTHER

Participants undergo two 120-minute euglycemic (90 mg/dL) hyperinsulinemic clamps - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit.Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Interventions

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Spironolactone

Participants will receive spironolactone 12 hours and 3 hours before the initiation of the hyperinsulinemic clamp treatment.

Intervention Type DRUG

Placebo

Participants will receive placebo 12 hours and 3 hours before the initiation of the hyperinsulinemic clamp treatment.

Intervention Type DRUG

Hypoglycemic Hyperinsulinemic Clamp

Participants undergo two 120-minute hypoglycemic (50 mg/dL) hyperinsulinemic clamps - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit. Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Intervention Type OTHER

Euglycemic Hyperinsulinemic Clamp

Participants undergo two 120-minute euglycemic (90 mg/dL) hyperinsulinemic clamps - an AM clamp from about 9 am to 11 am and a PM clamp from 1 pm to 3 pm on Day 2 of a 3-Day study visit.Modified Oxford Procedure is performed in duplicate at six time points - on Day 1, before the AM hyperinsulinemic clamp, during the AM hyperinsulinemic clamp, before the PM hyperinsulinemic clamp, during the PM hyperinsulinemic clamp, and on Day 3. The Modified Oxford procedure is performed to calculate baroreflex sensitivity.

Intervention Type OTHER

Other Intervention Names

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Hypoglycemic Hyperinsulinemic Clamp Procedure Euglycemic Hyperinsulinemic Clamp Procedure

Eligibility Criteria

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Inclusion Criteria

* Healthy volunteers
* Males and females age 18 to 55 years

Exclusion Criteria

* Pregnancy
* Lactation
* 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
* In all subjects, 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
* Known hypersensitivity to nitroglycerin, nitroprusside and/or phenylephrine.
* Blood pressure \> 140/90 mmHg
* Creatinine \> 1.5 mg/dL
* Serum potassium \>5.2 mmol/L
* Estimated GFR \< 50 mL/min
* Use of Viagra, Cialis, and similar drugs within 72 hours of admission.
Minimum Eligible Age

18 Years

Maximum Eligible Age

55 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Beth Israel Deaconess Medical Center

OTHER

Sponsor Role collaborator

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role collaborator

National Center for Advancing Translational Sciences (NCATS)

NIH

Sponsor Role collaborator

Brigham and Women's Hospital

OTHER

Sponsor Role lead

Responsible Party

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Gail Kurr Adler

Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Gail Adler, MD/PhD

Role: PRINCIPAL_INVESTIGATOR

Brigham and Women's Hospital

Roy Freeman, MD

Role: PRINCIPAL_INVESTIGATOR

Beth Israel Deaconess Medical Center

Locations

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Beth Israel Deaconess Medical Center

Boston, Massachusetts, United States

Site Status

Brigham and Women's Hospital

Boston, Massachusetts, United States

Site Status

Countries

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United States

Other Identifiers

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R01HL109634

Identifier Type: NIH

Identifier Source: secondary_id

View Link

K24HL103845

Identifier Type: NIH

Identifier Source: secondary_id

View Link

UL1TR001102

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2004P001233-B

Identifier Type: -

Identifier Source: org_study_id

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