Hypoglycemia (Low Blood Sugar) and the Heart

This study is not yet open for participant recruitment.
Verified January 2014 by University of British Columbia
Sponsor:
Information provided by (Responsible Party):
University of British Columbia
ClinicalTrials.gov Identifier:
NCT01980914
First received: November 4, 2013
Last updated: January 13, 2014
Last verified: January 2014
  Purpose

The risk of hypoglycemia (low blood sugar) associated with the treatment of diabetes increases with age. Hypoglycemia is a common reason for admission to hospital for older patients with diabetes. Older patients are often unaware that their blood sugar is low and asymptomatic hypoglycemia, as assessed by continuous blood sugar monitoring, is frequent in the elderly. There is also evidence that older people with diabetes are more likely to develop cardiovascular events such a heart attack and more likely to die suddenly when compared to older people without diabetes. It is possible that low blood sugar levels contribute to the increased frequency of these events, but this possibility has never been studied. The purpose of this study is to assess how frequently low blood sugar occurs in older patients with diabetes and to see if low blood sugars adversely affect heart function in these patients.


Condition
Hypoglycemia
Type 2 Diabetes

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Impact of Hypoglycemia on Cardiac Function in Elderly Patients With Diabetes

Resource links provided by NLM:


Further study details as provided by University of British Columbia:

Primary Outcome Measures:
  • blood sugar measurement [ Time Frame: 6 days ] [ Designated as safety issue: No ]
    Track hypoglycemia with continuous glucose monitor


Secondary Outcome Measures:
  • Monitor cardiac function [ Time Frame: 6 days ] [ Designated as safety issue: No ]
    Track alterations in cardiac rhythm, alterations in cardiovascular autonomic function and myocardial ischemia, collect baseline data to design a subsequent study to assess the effects of various interventions designed to protect the cardiovascular system against hypoglycemia.


Other Outcome Measures:
  • Correlation [ Time Frame: 6 days ] [ Designated as safety issue: No ]
    Try to correlate blood sugar (hypoglycemic events) and cardiac function (alterations in cardiac rhythm, alterations in cardiovascular autonomic function and myocardial ischemia).


Estimated Enrollment: 20
Study Start Date: February 2014
Estimated Study Completion Date: January 2015
Estimated Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Detailed Description:

Investigators propose a pilot study in 20 patients over age 70 who have type 2 diabetes and are being treated with insulin. These patients will be enrolled from the elderly diabetes clinic at Vancouver General Hospital. Patients will be asked to come to the Gerontology research laboratory in the Research Pavilion at Vancouver General Hospital. A trained research nurse will instrument each patient with an ipro 2 glucose sensor (Medtronic Canada). These sensors reliably and continuously measure blood glucose for periods of up to 7 days. Briefly, the skin will be swabbed with a disinfectant and a small catheter will be inserted subcutaneously. This needle will be attached to a glucose sensor. Patients will wear this sensor for 6 days. Patients will measure their glucose using a glucometer 4 times each day during this period and will also be given a log book to keep track of glucose values. Patients will also be asked to record any symptoms of hypoglycemia. At the end of 6 days the sensor will be removed.

At the same time the glucose sensor is started, a trained research nurse will connect the patient to a continuous ambulatory 12-lead ECG cardiac monitor (48 hour Holter monitor). The archived 12-lead ECG waveforms will be downloaded for QT and T-wave alternans analysis. The heart rate and QT interval will be measured at baseline and the end of each interval from the digitized 12-lead ECG.

Patients and relevant family will be provided with in person education regarding the function and use of the monitor, implications for bathing and sleep, and contact information for troubleshooting. Patients will have to return to the laboratory every 2 days to have the Holter monitor and the ECG leads replaced. Patients will be asked to keep a log book of any cardiac symptoms during the 6 days of the study, as well as their activities. The glucose and Holter monitor will undergo time synchronization to ensure ability to do correlative analysis.

This is a feasibility pilot to establish preliminary data for analysis. The Holter monitor will allow assessment of cardiac arrhythmias, myocardial ischemia and cardiovascular autonomic function. The results from the glucose sensor and the Holter monitor will be correlated and compared to each other to determine if hypoglycemia has an adverse effect on heart function. Hypoglycemia is likely to induce autonomic responses captured on the Holter and concordant ischemic S-T segment changes if coronary disease is present. It may also detect any resultant arrhythmias, although ischemic arrhythmias are uncommon in 6 days of monitoring. If investigators determine that hypoglycemia has negative effects on cardiac function, investigators may able to design treatments that would prevent these effects from happening in the future.

  Eligibility

Ages Eligible for Study:   70 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

These patients will be enrolled from the elderly diabetes clinic at Vancouver General Hospital.

Criteria

Inclusion Criteria:

  • 70 years old and over
  • had type 2 diabetes for at least 5 years
  • treated with insulin glargine.
  • BMI of between 20 and 35 Kg/M2,
  • A1c between 7 and 8.5 %.
  • well controlled hypertension and hyperlipidemia.

Exclusion Criteria:

  • cannot speak english or give informed consent, or cognitive impairment
  • glomerular filtration rate (GFR) less than 40ml/min,
  • poorly controlled Chronic Heart Failure
  • active coronary artery disease
  • active cerebrovascular disease although a past history of CAD or stroke will not results in exclusion.
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01980914

Locations
Canada, British Columbia
Vancouver Coastal Health Research Institute (VCHRI/VCHA) site -Vancouver General Hospital Not yet recruiting
Vancouver, British Columbia, Canada, V6M 1N7
Contact: Chris K Lockhart, BSc    604-875-4111 ext 68535    Chris.Lockhart@vch.ca   
Principal Investigator: Graydon S Meneilly, MD         
Sub-Investigator: Kenneth M Madden, MD, MSc         
Sub-Investigator: Andrew D Krahn, MD         
Sponsors and Collaborators
University of British Columbia
Investigators
Principal Investigator: Graydon S Meneilly, MD University of British Columbia
  More Information

No publications provided

Responsible Party: University of British Columbia
ClinicalTrials.gov Identifier: NCT01980914     History of Changes
Other Study ID Numbers: H13-02734, unfunded
Study First Received: November 4, 2013
Last Updated: January 13, 2014
Health Authority: Canada: Health Canada

Keywords provided by University of British Columbia:
hypoglycemia
type 2 diabetes
glargine
cardiac function
myocardial ischemia
cardiac rhythm
autonomic cardiovascular function

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Hypoglycemia
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases

ClinicalTrials.gov processed this record on April 17, 2014