Hypoglycemia Associated Autonomic Failure in Type 1 Diabetes Mellitus (DM)

Purpose

Exercise is a cornerstone of diabetes management. It helps reduce blood pressure, promote weight loss, lower insulin resistance and improve glucose and lipid (triglyceride and HDL-cholesterol) profiles. Unfortunately, the benefits of exercise are often not embraced by diabetic individuals because of the fear of low blood sugar (hypoglycemia). My laboratory has demonstrated that Autonomic nervous system (ANS) counterregulatory failure plays an important role in exercise associated hypoglycemia in Type 1 DM. ANS responses are significantly reduced in Type 1 DM and are further blunted by antecedent episodes of hypoglycemia. Furthermore, there is a large sexual dimorphism of reduced ANS responses during submaximal exercise in both Type 1 DM and healthy individuals that is unexplained. Accumulating data are demonstrating that serotonergic pathways can regulate ANS discharge. Generally, serotonergic pathways are inhibitory but both single and longer term administration of selective serotonin reuptake inhibitors (SSRI's) such as Prozac has been demonstrated to increase basal epinephrine levels and enhance baroreflex control of Sympathetic nervous system (SNS) activity. What is unknown is whether fluoxetine can also enhance SNS responses and also override the large ANS sexual dimorphism present during sub maximal exercise. Therefore, the purpose of this study is to determine if the SSRI fluoxetine (Prozac) can improve SNS responses during exercise.

Conditions

  • Type 1 Diabetes
  • Hypoglycemia Associated Autonomic Failure

Eligibility

Eligible Ages
Between 18 Years and 45 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • 32 (16 males, 16 females) Healthy controls aged 18-45 yr. - 32 (16 males, 16 females) Type 1 diabetic patients aged 18-45 yr. - HbA1c 6-10.0% - Has been diagnosed Type 1 DM - No clinically diagnosed diabetic tissue complications (i.e. history of retinopathy, neuropathy, stasis ulcers, etc) - Body mass index < 40kg • m-2

Exclusion Criteria

  • Pregnant women - Subjects unable to give voluntary informed consent - Subjects on anticoagulant drugs, anemic or with known bleeding diatheses - Subjects taking any of the following medications will be excluded: Non-selective Beta Blockers, Sedative-Hypnotics, Anticonvulsants, Antiparkinsonian drugs, Antipsychotics, Antidepressants, Mood stabilizers, CNS Stimulants, Opioids, Hallucinogens - Subjects with a recent medical illness - Subjects with a history of hypertension, heart disease, cerebrovascular incidents - Current tobacco use

Study Design

Phase
Early Phase 1
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Primary Purpose
Treatment
Masking
Double (Participant, Investigator)

Arm Groups

ArmDescriptionAssigned Intervention
Active Comparator
Trial 1-SSRI
90 minute exercise baseline with 6 weeks treatment with SSRI (Prozac). Repeat 90 minute exercise after 6 week treatment.
  • Drug: Fluoxetine
    20 mg week 1, 40 mg week 2, 60 mg week 3, 80 mg week 4-6
    Other names:
    • Prozac
Placebo Comparator
Trial 2-Placebo
90 minute exercise at baseline with 6 weeks treatment with placebo. Repeat 90 minute exercise after 6 weeks treatment of placebo.
  • Drug: Placebo control
    20 mg Week 1, 40 mg Week 2, 60 mg Week 3, 80 mg Week 4-6

Recruiting Locations

University of Maryland, Baltimore
Baltimore, Maryland 21201
Contact:
Maka Siamashvili, MD
410-706-5623

More Details

Status
Recruiting
Sponsor
University of Maryland, Baltimore

Study Contact

Maka Siamashvili, MD
410-706-5623
msiamashvili@som.umaryland.edu