Archive for December, 2009

Low vitamin D raises blood pressure in women: study

Saturday, December 26th, 2009

Younger white women with vitamin D deficiencies are about three times more likely to have high blood pressure in middle age than those with normal vitamin levels, according to a study released on Thursday.

The study, presented at a meeting of the American Heart Association in Chicago, adds younger women to a growing list of people including men who may develop high blood pressure at least in part because of low vitamin D.

Researchers in Michigan, who examined data on 559 women beginning in 1992, found that those with low levels of vitamin D were more likely to have high blood pressure 15 years later in 2007.

“Our results indicate that early vitamin D deficiency may increase the long-term risk of high blood pressure in women at mid-life,” said Flojaune Griffin, who worked on the study for the University of Michigan School of Public Health.

Vitamin D, which the human body can make from sunlight and which is found in fatty fish, fortified milk products and dietary supplements, has long been known to contribute to healthy bones and teeth.

But deficiencies, which are widespread in women, are linked to cancer, immune system problems and inflammatory diseases.

High blood pressure raises the likelihood of stroke, heart disease and other cardiovascular problems.

The women in the blood pressure study lived in Tecumseh, Michigan, and were 24 to 44 years old with an average age of 38, when the research began.

Researchers measured vitamin D blood levels at the outset and took blood pressure readings once a year. In 2007, they compared systolic readings — the top number in blood pressure results that indicates the pressure within blood vessels when the heart beats.

More than 10 percent of women with vitamin D deficiencies had high blood pressure in 2007, versus 3.7 percent of those with sufficient levels. When the study began, 5.5 percent with deficiencies also had high blood pressure, compared to 2.8 percent with normal vitamin D.

The study was funded by the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Almost half the population worldwide has lower-than-optimal levels of vitamin D and researchers say the problem is worsening as people spend more time indoors. African-Americans seem at especially high risk as dark skin can make it harder for the body to absorb ultraviolet light.

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Malaria parasite’s resistance to top drug grows: WHO

Saturday, December 19th, 2009

The World Health Organization warned on Wednesday that the parasite which causes malaria is increasingly resistant to artemisinin, the best drug around, and failure to contain this trend would bring serious consequences.

“This (Asia Pacific) region has traditionally been the focus of resistance to antimalarial drugs and now we have artemisinin resistance primarily on the Thai-Cambodian border,” said John Ehrenberg, WHO regional adviser on malaria and other vectorborne and parasitic diseases.

“If it is not contained, it can have global implications and the most serious one would be in Africa which has a high disease burden and the highest mortality rates,” he told Reuters on the sidelines of a regional meeting of the WHO in Hong Kong.

Although malaria is preventable and treatable, there were still between 189 million to 327 million cases in 2006, resulting in between 610,000 to 1.2 million deaths.

Half the world’s population is at risk, particularly the poor and those living in remote areas with limited healthcare access. A child dies from malaria every 30 seconds.

Artemisinin, derived from the sweet wormwood shrub, is the best drug available but misuse and over-prescription have led to the parasite becoming resistant to it.

The best way to prolong the use of the drug would be to use it in combination with other antimalarial drugs. Nearly all the

Asia Pacific region countries that suffer most from the disease pledged on Wednesday to do that.

“Experts have been calling for combined therapy to make sure this problem does not arise … all endemic countries in the region, except one, have adopted (the plan) and we are hoping to get the 10th pretty soon,” Ehrenberg said.

The 10 countries are Cambodia, China, Laos, Malaysia, Papua New Guinea, the Philippines, South Korea, Solomon Islands, Vanuatu and Vietnam. In 2008, these 10 states reported 248,141 confirmed cases of malaria and 1,005 deaths.

Under the agreement, the use of artemisinin alone for treating malaria must be banned by 2015.

All 10 states will also help fight counterfeit antimalarial drugs, again a major cause of deaths.

In recent years, parts of Asia have been awash with fake antimalarial drugs. They contain little or no active ingredient that would fight the disease and many people have died because of that. Some of the fakes have been traced back to illegal factories in China, according to experts.

“Low quality and counterfeit drugs is a serious concern … any inadequate way of treating malaria can lead to death. Malaria kills a lot of children especially in Africa when you don’t treat it properly, it leads to death,” Ehrenberg said.

“Many countries rely a lot on the private sector. Unregulated drug policy can jeopardize efforts to (drug) resistance containment. Getting the private sector onboard is critical.”

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Minorities Less Likely to Have Blood Pressure Under Control

Saturday, December 12th, 2009

Blacks and Hispanics with a history of stroke or coronary artery disease have higher blood pressure than whites, while Hispanics are less likely to be prescribed medications to control it, a new U.S. study shows.

About 63 percent of whites, 58 percent of Hispanics and 40 percent of blacks had blood pressure readings that fell within national guidelines, the researchers found.

“There was a significant disparity in achievement of blood pressure goals among African Americans as compared to whites or Hispanics,” said senior study author Dr. Nerses Sanossian, associate director of the Stroke Center at University of Southern California.

The study was to be presented Wednesday at the American Heart Association’s High Blood Pressure Research Conference in Chicago.

Researchers evaluated data on blood pressure levels from 517 participants in the National Health and Nutrition Examination Survey who reported having had either a stroke or coronary artery disease. About 12 percent of participants were Hispanic and 25 percent were black.

National recommendations call for most adults to keep their blood pressure under a reading of 140 for the top number and 90 for the lower number, while diabetics should keep it under 130/80.

“The greatest risk factor for having a heart attack or stroke is having a previous heart attack or stroke,” Sanossian said. “Blood pressure control is one of the cornerstones of prevention. This is a group of people in whom prevention is really crucial.”

Reasons for the disparities may include lifestyle or economic factors, genetics and differences in the quality of health care received, the researchers said.

While blacks and whites reported being prescribed blood pressure medications at similar rates, blood pressure was not as well-controlled in black patients as in white patients.

Black participants had average systolic blood pressure (the upper number in a reading) of 140, compared to 134 among whites. Blacks had diastolic blood pressure (the lower number) of 74, compared to 65 in whites. Both are significant differences, Sanossian noted.

Previous research shows that a systolic decrease of 10 translates into a 31 percent reduction in stroke rate.

“The average person out there has to have their blood pressure controlled, but if you’ve had a stroke or coronary artery disease you have to have your blood pressure controlled in a much stricter way,” Sanossian stressed.

Hispanics and whites had similar systolic blood pressure (133 compared to 134), though Hispanics had higher diastolic blood pressure (72 compared to 65), the researchers noted.

Yet, only 54 percent of Hispanics who’d had a stroke or who had coronary artery disease were taking drugs for hypertension, compared to 77 percent of whites and 76 percent of blacks.

Among stroke survivors, 52 percent of Hispanics were prescribed blood pressure medications compared to 74 percent of whites and 87 percent of blacks. Among Hispanics with coronary artery disease, about 59 percent were taking hypertension medications compared to 80 percent of whites and 74 percent of blacks.

Making sure that minorities get the proper blood pressure medication to get blood pressure under control is of critical importance, said Dr. Rhian M. Touyz, a professor of medicine at University of Ottawa.

Hypertension is more common in blacks than whites and tends to be more difficult to get under control, Touyz said. Blacks tend to suffer more severe complications from high blood pressure at a younger age than other racial groups. Blacks are also more sensitive to the effects of salt in the diet, which can raise blood pressure.

“It’s well known that African Americans tend to develop much worse renal complications and stroke than white patients with high blood pressure,” Touyz said. “If we can understand better what are the mechanisms that are responsible for the differences in hypertension rates and why the complications are more severe, it will allow us to better treat patients who are black.”

In addition, certain high blood pressure treatments don’t work as well in blacks. Classes of drugs that inhibit the renin-angiotensin system, which can raise blood pressure when overactive, tend to be more effective in whites, Touyz said.

The data used in the study did not include information about what medications participants were taking or the doses.

Education and outreach programs targeting minorities, along with aggressive screening and treatment for hypertension, would help eliminate some of the disparities, the researchers said

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New Parkinson’s Drug Draws Mixed Reviews

Saturday, December 5th, 2009

A study to see whether a new drug can stop the progression of Parkinson’s disease has produced results that have drawn sharply differing reactions from neurologists.

The drug, rasagiline (Azilect), was approved in 2006 by the U.S. Food and Drug Administration on the basis of studies showing that it reduced Parkinson’s symptoms such as trembling and slowed motion. The new study, reported in the Sept. 24 issue of the New England Journal of Medicine, was designed to determine whether the drug also acts on the underlying nerve deterioration that causes the disease.

“In our heart, what we are hoping for is neuroprotection,” said study author Dr. C. Warren Olanow, a professor of neurology and neuroscience at Mount Sinai School of Medicine, in New York City.

To distinguish the effect on symptoms from the hoped-for effect on the underlying disease, “we used a totally new study design, to see if it is disease-modifying,” Olanow explained.

The study enlisted 1,176 people with previously untreated Parkinson’s disease who were seen at medical centers around the world. At the start, half took daily doses of either 1 milligram or 2 milligrams of rasagiline for 36 weeks, while the other half took a placebo. After that, all the participants took either 1 milligram or 2 milligrams of rasagiline for another 36 weeks.

A complex system to measure the treatment effects showed an apparent improvement in the participants who took the 1-milligram doses but not in those taking the 2-milligram doses.

“It did something to affect the course of the disease,” Olanow said. “We don’t know why, but we are entitled to speculate.”

His speculation is based on a detailed study of the 25 percent of participants who showed the greatest benefit. “What I think is right is that the higher dose had a greater effect on symptoms than the lower dose, so that masked our ability to detect its effect on disease progression,” Olanow said. “We thought that this floor effect was why we couldn’t see a difference.”

Olanow was enthusiastic about the results. “This doesn’t prove unequivocally that it [rasagiline] is neuroprotective, but there is no other rational explanation for the results,” he said. “This is good news for Parkinson’s patients.”

Asked if he would prescribe the drug for that reason, Olanow said, “Yes, I would personally prescribe it.”

A much more skeptical response came from Dr. William J. Weiner, chair of neurology at the University of Maryland, who took part in the study.

“The authors were very careful in the paper not to indicate that they had shown neuroprotection,” Weiner said. “The tone of the article itself is moderate.”

The methods used to determine trial results need scrutiny, he said. “They used a lot of very fancy mathematical models, some of which had not been used before,” Weiner said. “Most neurologists wouldn’t understand the mathematical models they used. Research neurologists don’t deal with equations about the slope of curves.”

And the end results were not impressive, he maintained. “The difference reported in the study is less than two points on a scale that has 150 points,” Weiner said.

The reason why the lower dose worked, and the higher one didn’t? “It simply could be luck,” he said.

While rasagiline can provide benefits in reducing symptoms of early Parkinson’s disease, Weiner said he was worried that “patients will be given what I believe to be false hopes” by the new study.

“It has mild symptomatic effects, but I do not prescribe this drug for neuroprotection and this study doesn’t convince me to do that,” Weiner said.

Several of the study authors have received consulting or lecturing fees from pharmaceutical companies, including Teva, the maker of Azilect.

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