Navigation Links
Uncontrolled hypertension could bring increased risk for Alzheimer's disease
Date:3/18/2013

A study in the JAMA Neurology (formerly the Archives of Neurology) suggests that controlling or preventing risk factors such as hypertension earlier in life may limit or delay the brain changes associated with Alzheimer's disease and other age-related neurological deterioration.

Dr. Karen Rodrigue, assistant professor in the UT Dallas Center for Vital Longevity (CVL), was lead author on a study that looked at whether people with both hypertension and a common gene associated with risk of Alzheimer's disease (the APOE-4 gene carried by about 20 percent of the population) had more buildup of the brain plaque (amyloid protein) associated with Alzheimer's disease. Many scientists believe the amyloid plaque is the first symptom of Alzheimer's disease and shows up a decade or more before Alzheimer's symptoms of memory impairment and other cognitive difficulties begin.

Until recently, amyloid plaque could only be seen at autopsy, but new brain scanning techniques allow scientists to see the amyloid plaque in living brains of healthy adults. Findings from both autopsy and amyloid brain scans show that at least 20 percent of normal older adults carry elevated levels of amyloid, a substance made up mostly of protein and deposited in organs and tissues.

"I became interested in whether hypertension was related to increased risk of amyloid plaques in the brains of otherwise healthy people," Rodrigue said. "Identifying the most significant risk factors for amyloid deposition in seemingly healthy adults will be critical in advancing medical efforts aimed at prevention and early detection."

Based on evidence that hypertension was associated with Alzheimer's disease, Rodrigue suspected that the double-whammy of hypertension and presence of the APOE-e4 gene might lead to particularly high levels of amyloid plaque in healthy adults.

Rodrigue's research was part of the Dallas Lifespan Brain Study, a comprehensive study of the aging brain in a large group of adults of all ages funded by the National Institute on Aging. As part of this study, the research team recruited 147 participants (ages 30-89) to undergo cognitive testing, magnetic resonance imaging (MRI) and PET imaging, using Amyvid, a compound that when injected travels to the brain and binds with amyloid proteins, allowing the scientists to visualize the amount of amyloid plaque. Blood pressure was measured at each visit.

Rodrigue classified participants in the study as hypertensive if they reported a current physician diagnosis of hypertension or if their blood pressure exceeded the established criteria for diagnosis. The participants were further divided between individuals who were taking anti-hypertensive medications and those who were not medicated, but showed blood pressure elevations consistent with a diagnosis of hypertension. Finally, study subjects were classified in the genetic risk group if they were in the 20 percent of adults who had one or two copies of an APOE ε4 allele, a genetic variation linked to dementia.

The most striking result of the study was that unmedicated hypertensive adults who also carried a genetic risk factor for Alzheimer's disease, showed much higher amyloid levels than all other groups. Adults taking hypertensive medications, even those with genetic risk, had levels of amyloid plaque equivalent to participants without hypertension or genetic risk.

The study suggests that controlling hypertension may significantly decrease the risk of developing amyloid deposits, even in those with genetic risk, in healthy middle-aged and older adults. Rodrigue noted that long-term studies of many people were needed to be certain that it was the use of hypertensive medications that was causal of the decreased amyloid deposits. Nevertheless, this early finding provides a window into the potential benefits of controlling hypertension that goes beyond decreasing risk of strokes and other cardiovascular complications.

Scientists cannot fully explain the neural mechanisms underlying the effect of hypertension and APOE ε4 on amyloid accumulation. But earlier research in animal models showed that chronic hypertension may enable easier penetration of the blood-brain barrier, resulting in more amyloid deposition.

The recent study is significant because it focuses on a group of healthy and cognitively normal middle-aged and older adults, which enables the examination of risk factors and amyloid burden before the development of preclinical dementia. The team plans for long-term longitudinal follow-up with participants to determine which proportion of the subjects eventually develop the disease.

The study's coauthors included Dr. Denise Park, director of the Dallas Lifespan Brain Study, and Dr. Kristen Kennedy and doctoral student Jennifer Rieck, all from The University of Texas at Dallas. The team also included Dr. Michael Devous and Dr. Ramon Diaz-Arrastia, scientists from UT Southwestern Medical Center and the Uniformed Services University of the Health Sciences. In addition to the National Institute on Aging, the Alzheimer's Association provided funds for the study. Avid Radiopharmaceutical provided doses of Amyvid that allowed the researchers to image the amyloid plaque with a PET scan.


'/>"/>

Contact: Emily Martinez
emily.martinez@utdallas.edu
972-345-0061
University of Texas at Dallas
Source:Eurekalert

Related medicine news :

1. Uncontrolled Risk Factors Put Stroke Survivors in Danger
2. Millions of Americans Have Uncontrolled High Blood Pressure: CDC
3. NIH awards $12.4 million grant to fund Henry Ford Hospital hypertension research
4. First-Born May Be at Greater Risk for Diabetes, Hypertension
5. Black patients with hypertension not prescribed diuretics enough
6. Hypertension during pregnancy increases risk of end-stage renal disease
7. UC Davis study links low wages with hypertension, especially for women and younger workers
8. MyBloodWorks Creator Glen Ogle Comments on New Study Linking Hypertension During Pregnancy to Later Heart Trouble
9. Treating Kidneys With Radio Waves May Ease Tough-to-Control Hypertension
10. NY-Presbyterian Hospital announces participation in trial for hard-to-treat hypertension
11. Kidney stenting lowers blood pressure in patients with severe hypertension
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/31/2016)... ... May 31, 2016 , ... In his latest video, ... traits in humans. Using presidential candidate Donald Trump as an example, Kalsi describes ... “AstroNumerology is not about adding numbers up,” says Kalsi. “It is about looking ...
(Date:5/31/2016)... , ... May 31, 2016 , ... Phynd Technologies, Inc. ... GA; Houston Methodist – Houston, TX and Shore Medical Center – Somers Point, NJ. ... three different, leading EHR solutions, demonstrating the breadth of Phynd’s solution and its interoperability. ...
(Date:5/31/2016)... ... May 31, 2016 , ... Dr. Charles A. Ditta ... of New Jersey in the class of 1986, where he graduated in the top ... his current location in Livingston since 1989. He has been a member in good ...
(Date:5/31/2016)... ... ... Super Powder, a supplement produced by Prox Formulas for providing protein ... to transform the nutritional supplement industry by providing a safe, natural approach to enhanced ... (BCAA), alkaline minerals, wheat grass, digestive enzymes, Omega 3’s, Vit D3, Vit A, B1, ...
(Date:5/30/2016)... ... May 30, 2016 , ... ... Shaolin warrior 8-day-8 and 8-night special intensive summer training camp starts on June ... summer camp offers families and children a fun and unique experience with an ...
Breaking Medicine News(10 mins):
(Date:5/27/2016)... 2016 According to the 2016 ... driving ambulatory blood pressure monitoring system market growth. With ... ability to respond to different pressure rates, leading to ... to various cardiovascular disorders such as heart failure, stroke, ... are growing in prevalence each year. WHO estimates that ...
(Date:5/26/2016)... May 26, 2016 According to a ... Management Market - U.S. Industry Analysis, Size, Share, Growth, Trends, ... in the U.S. was valued at US$ 5.89 Bn in ... 3.4% from 2015 to 2023 to reach US$ 7.99 Bn ... current and emerging needle free drug delivery devices and the ...
(Date:5/25/2016)... May 25,2016 FDA 510(k) ... Cellvizio platform for urological and surgical applications ... inventor of Cellvizio®, the multidisciplinary confocal laser endomicroscopy ... in the US with the 12 th ... Administration (FDA). This new FDA clearance covers Confocal ...
Breaking Medicine Technology: