Tight blood pressure control not enough to temper kidney disease in African-Americans
April 28, 2008Even when their blood pressure is kept strictly under control with the best available medicine, African-American patients with chronic kidney disease (CKD) continue to lose their kidney function over time, research led by a Johns Hopkins team shows. The finding suggests that treating CKD in this population may be vastly more complex than researchers had previously thought, with blood pressure control being only one piece of the therapeutic puzzle.
The study, called AASK (African-American Study of Kidney Disease and Hypertension), is the longest to date focusing on blood pressure in patients with CKD. AASK followed 1,094 African-American patients with this condition for up to 11 years. Through a combination of medications, most of these patients kept their blood pressure in the recommended range for CKD, lower than 130/80. However, the vast majority still went on to develop steadily worsening kidney function, often leading to dialysis, kidney transplantation, or death.
“Kidney disease still progressed at an alarming rate, even when our participants received outstanding medical care for their high blood pressure,” says study leader Lawrence Appel, M.D., professor of medicine at the Johns Hopkins School of Medicine. “Blood pressure is important, but it’s not the whole picture. We still have a long way to go in figuring out the best way to treat patients with CKD.”
Appel and his colleagues at 21 clinical centers across the country chose to focus their study on African Americans, who suffer disproportionately from kidney disease associated with high blood pressure. In whites, high blood pressure causes about 19 percent of all end-stage renal disease cases, in which kidneys have essentially lost their function. In African-Americans, the corresponding figure is about 37 percent.
Researchers aren’t sure why high blood pressure often leads to CKD. The prevailing theory is that high pressure strains delicate tufts of capillaries known as glomeruli, which filter blood and create urine in kidneys.
To investigate whether keeping blood pressure low would slow or possibly stop CKD progression, the researchers designed their study in two phases; the first would take place between February 1995 and September 2001, and the second between October 2001 and June 2007.
In the first phase, the researchers randomly assigned all 1,094 patients to one of three drugs commonly used to lower blood pressure-an ACE inhibitor, a â-blocker, or a calcium channel blocker. Each patient was also assigned to one of two blood pressure goals-a standard goal (about 140/90 or lower), and a more aggressive goal (130/80 or lower). The researchers tracked each patient’s blood pressure and kidney function, determined through blood and urine tests, as well as their overall health.
At the end of the first phase, the researchers found that about a third of the patients had lost at least half their kidney function, developed end-stage renal disease, or died, even though almost all of the patients were well within their blood pressure goals. Of the remaining patients, the scientists recruited 759 to continue on to the study’s next phase, in which they capitalized on what they’d learned so far. Early findings from the first phase showed that the ACE inhibitor worked better than the other treatments, so the remaining patients began taking that drug. They were also given the more aggressive blood pressure goal of 130/80.
Over the next five years, the researchers again tracked patients’ blood pressure, kidney function, and overall health. However, regardless of their new and improved treatment, a third of these patients still lost at least half their kidney function, developed end-stage renal disease, or died.
These results, published in the April 28 Archives of Internal Medicine, shouldn’t discourage patients with CKD from continuing their blood pressure therapy, says Appel. “Outcomes would certainly be worse if they didn’t control their blood pressure,” he explains. However, he adds that the findings suggest that other factors beyond just blood pressure may be at play in worsening CKD. Blood pressure spikes at night, high salt intake, or exposure to heavy metals like lead or mercury may influence kidney disease progression. “Lots of different factors need examining,” says Appel.
Source: Johns Hopkins Medical Institutions
-
Stanford develops new tool for teaching doctors to treat sepsis
Feb 09, 2012 |
5 / 5 (2) |
0
-
Goals for blood pressure in kidney disease patients may be unrealistic
Feb 02, 2012 |
not rated yet |
0
-
Rare kidney disease shows how salt, potassium levels are moderated
Jan 23, 2012 |
1 / 5 (1) |
0
-
Anemia may more than triple your risk of dying after a stroke
Feb 02, 2012 |
not rated yet |
0
-
Sleep deprivation tied to increased nighttime urination in preadolescence
Feb 01, 2012 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
-
Is Everyday Technology Killing Us?
Feb 08, 2012
-
Exercise and weight loss
Feb 08, 2012
-
Why do we have head aches? Our brains can't feel anything.
Feb 07, 2012
-
"The end of diseases" by David Agus, interview from Daily Show with Jon Stewart
Feb 04, 2012
-
Oncolytic adenovirus
Feb 04, 2012
-
Nutrition label stuffs and diets
Feb 02, 2012
- More from Physics Forums - Medical Sciences
More news stories
Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV
A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...
10 hours ago |
5 / 5 (2) |
0
|
Overeating may double risk of memory loss
New research suggests that consuming between 2,100 and 6,000 calories per day may double the risk of memory loss, or mild cognitive impairment (MCI), among people age 70 and older. The study was released today and will be ...
Medicine & Health / Neuroscience
6 hours ago |
5 / 5 (2) |
0
|
Injured boomers beware: Know when to see doctor
(AP) -- It happened to nurse Jane Byron years after an in-line skating fall, business owner Haralee Weintraub while doing "men's" push-ups, and avid cyclist Gene Wilberg while lifting a heavy box.
11 hours ago |
5 / 5 (1) |
0
Declining health-care productivity in England: Who says so?
Reports that the National Health Service in England has been declining in productivity in the last decade appear to have been accepted as fact. However, a Viewpoint published Online First by The Lancet disputes this. The Vi ...
4 hours ago |
not rated yet |
0
FDA-approved drug rapidly clears amyloid from the brain, reverses Alzheimer's symptoms in mice
Neuroscientists at Case Western Reserve University School of Medicine have made a dramatic breakthrough in their efforts to find a cure for Alzheimer's disease. The researchers' findings, published in the journal Science, show t ...
Medicine & Health / Neuroscience
Feb 09, 2012 |
4.9 / 5 (58) |
17
|
Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy
For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...
New method to examine batteries -- MRI from the inside
There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...
Google might launch Drive for cloud storage soon
(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
Lab study raises questions over nano-particle impact
Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.
Researchers find extensive RNA editing in human transcriptome
In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...