Insulin Therapy and Falls Due to Orthostatic Hypotension
In the proposed study, the investigators examine in older adults with Type 2 diabetes the impact of beginning insulin therapy on the orthostatic drop in blood pressure as well as the response of arterial blood pressure and Doppler measures of cerebral blood flow during upright tilt. The investigators hypothesize that in older adults with Type 2 diabetes, the cardiovascular effects of insulin would precipitate or worsen orthostatic intolerance not present at baseline.
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Safety Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||Insulin Therapy and Falls Due to Orthostatic Hypotension (Pilot Study)|
- 1. Presence or absence of orthostatic hypotension [ Time Frame: 1 day ] [ Designated as safety issue: Yes ]defined as a drop in systolic blood pressure greater than 20 mmHg after 3 minutes upright standing
- 1. The nadir of middle cerebral artery (MCA) velocity [ Time Frame: 1 day ] [ Designated as safety issue: Yes ]lowest middle cerebral artery flow velocity determined by transcranial Doppler
- 2. The presence or absence of a positive augmented tilt table test [ Time Frame: 1 day ] [ Designated as safety issue: Yes ]The augmented tilt table test will occur after receiving 300 μg nitroglycerin (GTN), and is a recognized method of testing for risk of vasovagal syncope. The tilt table will be considered positive and aborted prior to the 20 minutes if the subjects have a syncopal spell or demonstrate presyncopal (lightheadedness) symptoms in association with a 30 mm Hg drop in systolic blood pressure.
- 3. The nadir of systolic blood pressure (SBP) and diastolic blood pressure (DBP) during tilt table test. [ Time Frame: 1 day ] [ Designated as safety issue: Yes ]lowest systolic blood pressure and diastolic blood pressure during tilt table tests and when they occur.
|Study Start Date:||April 2015|
|Estimated Study Completion Date:||December 2016|
|Estimated Primary Completion Date:||September 2016 (Final data collection date for primary outcome measure)|
Before Initiation of Insulin Therapy
Study sessions will occur before the initiation of insulin therapy (no insulin). Initiation of insulin administration will be determined as part of standard of care by the subjects diabetologist in the VGH Diabetes Centre and not as part of participation in this study.
Other: No Insulin
Study session will occur prior to initiation of insulin therapy.
After Initiation of Insulin Therapy
Study session will take place 2-4 weeks after the initiation of insulin therapy. Initiation of insulin administration will be determined as part of standard of care by the subjects diabetologist in the VGH Diabetes Centre and not as part of participation in this study.
Initiation of insulin administration will be determined as part of standard of care by the subjects diabetologist in the VGH Diabetes Centre and not as part of participation in this study.
Other Name: Lantus
Before and 2 weeks after the start of standard insulin therapy several tests will be done:
- orthostatic hypotension will be tested for with 3 orthostatic maneuvers
- vasovagal syncope will be tested with 2 tilt table tests, one augmented with 400ug of nitroglycerin
- MCA velocity will be measured with a transcranial doppler
- Heart Rate and Blood Pressure will be measured throughout the test with a Finometer and Power Lab on a beat to beat basis
Please refer to this study by its ClinicalTrials.gov identifier: NCT01914146
|Canada, British Columbia|
|Gerontology Research Lab, Dept. of Medicine, Vancouver Coastal Health Research Institute, VGH Research Pavilion, Room 186-828 West 10th Avenue|
|Vancouver, British Columbia, Canada, V5Z 1M9|
|Principal Investigator:||Kenneth M Madden, MD||University of British Columbia|