| City: |
|
Dallas |
|
State:
|
|
TX |
| Zip Code: |
|
75390 |
| Conditions: |
|
Hypertension |
| Purpose: |
|
Thiazide medications are often prescribed for individuals with high blood pressure, but
research has shown that they may increase an individual's risk of developing diabetes. While
it is unknown exactly how thiazide causes this response, it is likely that the nervous
system is somehow involved. This study will evaluate the role of the nervous system in sugar
metabolism, as well as determine the effect of thiazide and other medications on individuals
with high blood pressure.
|
| Study summary: |
|
Thiazide medications, including chlorthalidone, are commonly prescribed for individuals with
high blood pressure because they are inexpensive, effective at lowering blood pressure, and
able to reduce the risk of heart failure and stroke. Despite these advantages, research has
shown that thiazide medications may increase an individual's risk of developing diabetes.
The exact mechanism that causes this remains unknown. Thiazide appears to increase
sympathetic nervous system activity, thereby decreasing glucose reuptake and metabolism by
skeletal muscle tissues. In turn, this tends to contribute to glucose intolerance and the
development of diabetes. More research, however, is needed to confirm this link.
Spironolactone, another blood pressure medication, does not pose the same risk for
developing diabetes and may prove beneficial as a primary treatment for high blood pressure.
The purpose of this study is to determine the role of the sympathetic nervous system in
glucose metabolism in individuals with high blood pressure, as well as compare the
effectiveness of thiazide, spironolactone, and other antihypertensive medications in
reducing blood pressure. Results from this study may initiate the development of future
clinical trials involving spironolactone as a primary treatment for reducing blood pressure.
This study will enroll individuals with high blood pressure. Participants will be assigned
to one of eight treatment groups. Depending on the assigned group, participants will receive
chlorthalidone, spironolactone, quinapril, irbesartan, eplerenone, or a combination of these
drugs, with or without placebo. Participants will attend four to six study visits over a
period of 16 to 28 weeks. All participants will attend a baseline study visit, which will
include a physical examination, a medical history review, vital sign measurements, and blood
and urine collection. Small electrodes will be used to measure muscle nerve activity. In
addition, blood pressure will be monitored continuously for 24 hours prior to the start of
the study. Depending on the assigned treatment group, study visits may include blood
collection, blood pressure monitoring, an electrocardiogram (ECG) to record heart activity,
nerve function monitoring, and/or plasma volume measurements. Participants' baroreflex
sensitivity may also be measured by monitoring nerve ending responses within the heart and
blood vessels. Insulin sensitivity will be measured with a glucose tolerance test and by
evaluating skeletal muscle glucose uptake. |
| Criteria: |
|
Inclusion Criteria:
- Untreated stage 1 primary hypertension (systolic blood pressure between 140 to 159 mm
Hg and diastolic blood pressure between 90 to 99 mm Hg)
Exclusion Criteria:
- Cardiopulmonary disease, as determined by medical history or by physical examination
- Serum creatinine greater than or equal to 1.5 mg/dL
- Diabetes mellitus or other systemic illness
- Left ventricular hypertrophy by echocardiography or ECG
- Hypersensitivity to chlorthalidone, spironolactone, eplerenone, angiotensin
converting enzyme (ACE) inhibitors, angiotensin receptor blocker, insulin, Evans
blue dye, or clonidine
- History of substance abuse (other than tobacco)
- History of gouty arthritis
- History of ACE inhibitor-induced cough or angioedema
- Evidence of secondary hypertension
- Pregnant |
|
|
|
| Study is available at: |
|
University of Texas Southwestern Medical Center at Dallas
Dallas, TX 75390
United States
Primary Contact:
Debbie Arbique, RN
Email: debbie.arbique@utsouthwestern.edu
Phone: 214-648-2968
Secondary Contact:
Wanpen Vongpatanasin, MD
Email: Wanpen.Vongpatanasin@UTSouthwestern.edu
Phone: 214-648-7950 |
|
|
If you are interested in this clinical trial please use the contact information above. If you would like to get additional information about this clinical trial please visit ClinicalTrials.gov.
|
| Trials Alerts: |
|
If you would like to be
notified of new clinical trials as they become available please
register for a free account.
|
|
| Data Source: |
|
ClinicalTrials.gov |
| Date Processed: |
|
March 21, 2011 |
Modifications to
this listing: |
|
Only selected fields are shown, please use the link
above to view all information about this clinical trial. |
|
|
|
|
|
|
|
|