Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene at heart of bad outcomes in high blood pressure patients

18.11.2005


Finding advances efforts to tailor drugs to individual patients



Having high blood pressure and a particular genetic alteration dramatically increases the risk of heart attack, stroke or death, and may explain why some hypertensive patients fare worse than others - even if they take the same medication, University of Florida researchers announced this week.

The discovery, reported at the annual Scientific Sessions of the American Heart Association, brings scientists a step closer toward determining how certain genes influence the development of hypertension and the bad outcomes associated with the condition. Just as discriminating shoppers buy made-to-order suits to flatter their figure, this type of research may someday enable patients to seek out medicine tailored to fit, based not on their size and shape but on their genetic makeup.


UF researchers studied about 5,700 patients ages 50 and older who were participating in a National Institutes of Health-funded substudy of the International Verapamil SR-Trandolapril study, or INVEST-GENES. Other scientists had previously found that hypertensive patients with a certain version of the alpha-adducin gene were less likely to suffer a heart attack or stroke if they were taking a diuretic.

"Specifically, their data suggested that one genotype group benefited from the diuretic and had a reduction in heart attack and stroke, while the other genotype group did not," said Julie Johnson, Pharm.D., director of the UF Center for Pharmacogenomics and chairwoman of the department of pharmacy practice at UF’s College of Pharmacy. "We felt we had an ideal population for trying to replicate this finding, which if true could have important clinical implications.

"In our study, carriers of the genetic variation had an approximately 43 percent higher risk of death, heart attack or stroke," she said. "Thus, this helps us piece together the puzzle of the various genes that lead to some people having worse outcomes than others when they have hypertension."

Genes likely determine nearly half one’s risk of developing hypertension, and factors such as diet, age, health status and the environment determine the rest. Similarly, certain genes are associated with the risk of the adverse consequences of hypertension, such as heart attack, stroke and kidney failure, said Johnson, a member of the UF Genetics Institute.

"One of the goals of our research is to identify the genes that are related to patient-to-patient differences in response to medications," Johnson said. "Personalizing drugs based on genetic makeup instead of taking a trial-and-error approach could lead to safer, more effective treatments for individual patients."

About 65 million Americans have high blood pressure, and another 25 million are at high risk of developing hypertension in the next decade, Johnson said. Elevated blood pressure is associated with kidney disease and up to half of all cases of coronary artery disease, the No. 1 killer of men and women in the United States. Many patients fail to achieve targeted blood pressure goals.

In the INVEST substudy, nearly a third of the participants were carriers of the tryptophan version of the alpha-adducin gene, a protein associated with the movement of ions, especially sodium, across cells. In these individuals, the amino acid glycine has been swapped with the amino acid tryptophan. Up to 40 percent of the population carries at least one copy of the tryptophan form of the gene.

In the UF study, those with this version had a 43 percent higher risk of heart attack, stroke or death than those with the glycine form in the 2 ½ years after the study began; 258 patients, about 5 percent, experienced a heart attack or stroke, or died. But unlike previous research, the UF study did not show that patients with the glycine form benefited more from diuretics, which help lower blood pressure by ridding the body of excess salt and water.

"We were not able to show any relationship between the genetic variations and benefits associated with diuretic therapy," Johnson said. "Thus, our data suggest that we would not use this genetic information to help determine who should get a diuretic. However, it does provide us clues into at least one gene that likely places people at risk for death, heart attack and stroke, and so perhaps in the future this information can be used to be more aggressive in the preventive therapies for these individuals."

As researchers learn more, they hope to better understand the complex interplay between genes, disease development and the treatments that work best depending on one’s DNA. For now, identifying patients at risk remains a challenge, and treatment is often inadequate, Johnson said.

"There are five first-line drug classes, with probably an average of seven to eight drugs in each class, then an additional half-dozen or so other drug classes that aren’t considered first-line," Johnson said. "This means there are many choices for drug therapy in hypertension - a good thing - but also adds to the trial-and-error element of finding the right drug for the right person, as any specific drug has only about a 50 percent chance of being effective in a specific patient."

Identifying genetic risk factors is only the first step, said epidemiologist Sharon Kardia, Ph.D., director of the Public Health Genetics Program at the University of Michigan School of Public Health.

"Large research studies need to be undertaken to prove that genetic risk can be reduced through medical or public health interventions. Second, this whole new realm of genomic medicine greatly expands the responsibilities of doctors, nurses and pharmacist to assure the proper use of genetic information in prescribing, dispensing and administering drug therapies," Kardia said. "Lastly, we have to tread lightly until we have assurances that people’s genetic information will be properly protected so that identifying someone as more expensive or difficult to treat won’t result in insurance or perhaps job discrimination. As Dr. Johnson’s research illustrates, we now have good evidence that we should be investing in genetics education, regulation and social engagement so that we can move these results to the next level - namely, decreasing health-care costs and saving lives."

Melanie Ross | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Studies and Analyses:

nachricht Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>