Examining Genetic Influence on Response to Beta-Blocker Medications in People With Type 2 Diabetes

Uncoupling Protein Polymorphisms and Cardiometabolic Responses to Beta-Blockers

Beta-blockers are medications used to treat cardiovascular disease (CVD) symptoms, including high blood pressure and chest pain. People with diabetes who receive beta-blockers may experience adverse health effects, but the exact cause of why this happens remains unknown. This study will examine the genetic factors that may influence how atenolol, a beta-blocker medication, affects fat breakdown, blood sugar levels, and heart function in people with type 2 diabetes.

Study Overview

• Status: Terminated
• Conditions: Diabetes Mellitus, Type 2
• Intervention / Treatment: Drug: Atenolol

Detailed Description

People with diabetes who develop CVD have worse health outcomes than people without diabetes who develop CVD. Beta-blockers are medications used to treat high blood pressure, angina (i.e., chest pain), arrhythmias, and other CVD conditions. While beta-blockers are effective at treating these conditions, they may also have damaging effects on cholesterol or glucose levels, thereby possibly lessening their ability to prevent CVD events in people with diabetes. It is important to identify which patients may not benefit from receiving beta-blocker medications. Genetic factors may influence how people respond to beta-blocker medications. The purpose of this study is to evaluate the influence of genetic variation on beta-blocker-induced changes in insulin sensitivity, fat breakdown, and heart function in people with type 2 diabetes.

This study will enroll people with type 2 diabetes. At a series of up to three baseline study visits, participants will have a blood collection, a glucose tolerance test, an echocardiogram to obtain images of the heart, and biopsies of muscle from the thigh and fat from the stomach. All participants will then receive atenolol once a day for 8 weeks. During Week 1, participants will receive a low dose of atenolol. They will then attend a study visit at the end of Week 1, and study researchers will examine how well participants are tolerating the medication. If the atenolol is well tolerated, the dose will be increased. Study researchers will call participants 1 week after any dosage changes to monitor for side effects. Blood collection will occur again at a study visit at Week 4. At Week 8, participants will then attend up to three study visits for repeat baseline testing. Participants will then be slowly tapered off of atenolol over a 1-week period.

• Study Type: Interventional
• Enrollment (Actual): 31
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Type 2 diabetes
• Pre-Diabetes

Exclusion Criteria:

• Insulin therapy
• Treatment with any beta-blocker in the 30 days before study entry
• Asthma
• Chronic obstructive pulmonary disease (COPD)
• Greater than first degree heart block
• Heart rate less than 60 bpm
• Systolic blood pressure less than 90 mm Hg
• Raynaud's phenomenon
• Known history of angina, heart attack, heart failure, coronary revascularization, or automatic implantable cardioverter defibrillators
• Pregnant
• Creatinine clearance less than 35 ml/min
• Hematologic dysfunction (white blood cell [WBC] count less than 3000 or hematocrit less than 28%)
• Allergy to amide anesthetics

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Atenolol; Participants will receive atenolol for 8 weeks.	Drug: Atenolol; 12.5 mg twice daily of atenolol for 1 week; increased to 25 mg twice daily for a total of 8 weeks, if the medication is well tolerated

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Diastolic Function (Annular Tissue Velocity [Em])		8 weeks
Change in Free Fatty Acid Kinetics	Estimate of peripheral lipolysis using modeling of free fatty acid levels collected during an IV glucose tolerance test. The change in threshold for insulin action (post-atenolol minus pre-atenolol) is the primary variable from this modeling that we analyzed.	Baseline and Week 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Triglycerides	(Post atenolol triglycerides - Pre atenolol triglycerides)	Baseline and Week 8
Change in Insulin Sensitivity	As measured by the Homeostatic model assessment of insulin resistance (HOMA2-IR) (post atenolol - pre atenolol). he Homeostatic model assessment (HOMA) is a method for assessing insulin sensitivity from fasting glucose and insulin. A higher HOMA value indicates higher insulin resistance. The widely-used formulae available for HOMA1 provide only linear approximations of HOMA_%B and HOMA_IR, the inverse of HOMA_%S. These are: HOMA1_IR = [FPI (uU/ml) x FPG (mmol/l) ]/22.5 HOMA1_%B = (20 x FPI)/(FPG - 3.5) The results obtained for HOMA2 may differ considerably from HOMA1 computer-calculated values, especially for more extreme glucose and insulin values. For this reason, no attempt has been made to provide linear approximations of HOMA2 calculated values of HOMA_%B, HOMA_IR and HOMA_%S. The software needed to calculate HOMA2 values is available on this website: https://www.dtu.ox.ac.uk/homacalculator/download.php, subject to the conditions specified on the downloads page.	Baseline and Week 8
Change in Glucose Effectiveness	Glucose effectiveness as measured by insulin-modified IV glucose tolerance test using the MINMOD model.	Baseline and Week 8
Change in HDL		Baseline and Week 8
Change in Insulin	fasting insulin (post - pre atenolol)	Baseline and Week 8

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: Amber L. Beitelshees, PharmD, MPH, University of Maryland, Baltimore

Study record dates

Study Major Dates

• Study Start: December 1, 2009
• Primary Completion (Actual): June 1, 2013
• Study Completion (Actual): May 1, 2014

Study Registration Dates

• First Submitted: June 17, 2009
• First Submitted That Met QC Criteria: June 17, 2009
• First Posted (Estimate): June 19, 2009

Study Record Updates

• Last Update Posted (Actual): September 26, 2019
• Last Update Submitted That Met QC Criteria: September 24, 2019
• Last Verified: September 1, 2019

More Information

Terms related to this study

• Keywords: Diabetes; Genetic; Atenolol
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2; Physiological Effects of Drugs; Adrenergic beta-Antagonists; Adrenergic Antagonists; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Antihypertensive Agents; Autonomic Agents; Peripheral Nervous System Agents; Sympatholytics; Adrenergic beta-1 Receptor Antagonists; Atenolol
• Other Study ID Numbers: HP-00040291; K23HL091120 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No