Study Knocks Hair Analysis
CHICAGO (AP) -- Hair analysis is generally an unreliable method of diagnosing nutritional problems and exposure to environmental toxins, according to a study of six commercial laboratories.
A hair sample sent to all six labs produced widely varying and often opposite results. One lab called the patient a ''fast metabolizer'' and recommended that she abstain from vitamin A; another said the sample showed she was a ''slow metabolizer'' who should take vitamin A supplements.
''Health-care choices based on these analyses may be ineffective or even detrimental to the patient's overall health,'' the researchers said in Wednesday's Journal of the American Medical Association.
A similar study made a similar warning in the same journal 15 years ago. Because laboratory methods have generally improved since then and a federal law was passed in 1988 to regulate testing, the researchers decided to re-examine the issue.
The hair -- supplied by one of the researchers -- was not tested for illegal drugs such as cocaine, which is another common use of hair analysis. The researchers did not pass judgment on the reliability of hair tests to detect drug use.
The authors, from the California Department of Health Services, said the federal government should refrain from certifying hair analysis laboratories until standards for proficiency testing are developed.
The researchers said an average of 225,000 hair mineral tests costing $9.6 million are performed yearly by nine labs nationwide. They focused on six, whose charges ranged from $30 to $69 per sample to test for levels of poisons such as arsenic and 18 other elements, including lead and mercury.
Because of the findings, health care professionals should reconsider the use of hair analysis to assess a patient's nutritional health, Steven Steindel of the Centers for Disease Control and Prevention and Dr. Peter Howanitz of the State University of New York in Brooklyn wrote in an accompanying editorial.
STD Linked to Cervical Cancer
CHICAGO (AP) -- Some strains of the common sexually transmitted disease chlamydia appear to raise women's risk of cervical cancer as much as sixfold, researchers say.
Another common sexually transmitted disease, human papillomavirus, or HPV, is known to be the leading cause of cervical cancer, but the risks of chlamydia have been much less clear.
The new findings, based on 128 women with advanced cervical cancer in Finland, Sweden and Norway, appear in Wednesday's Journal of the American Medical Association.
The findings ''suggest that cervical malignancy should be added to the complications and costs associated with genital chlamydial infections,'' Dr. Jonathan Zenilman of Johns Hopkins School of Medicine wrote in an accompanying editorial.
Chlamydia is the most common bacterial STD in the United States, with between 4 million and 8 million new cases reported yearly. Unlike HPV, it can be treated with antibiotics, but many women have no symptoms and the disease can cause pelvic inflammatory disease and infertility.
About 13,000 cases of cervical cancer are diagnosed annually, and though Pap tests can detect many cases in early, treatable stages, it kills about 4,600 women each year.
The researchers, led by Dr. Tarja Anttila of Finland's National Public Health Institute, examined data on women diagnosed with cervical cancer at least a year after having blood tests during health exams.
Blood was measured for exposure to 10 types of chlamydia. Three specific types were linked to cervical cancer, and one known as serotype G carried the highest risk. Women with that type of chlamydia were about 6.5 times more likely to develop cervical cancer than uninfected women.
The researchers took into account the effects of HPV and smoking, another risk factor for cervical cancer.
How a bacterial infection such as chlamydia might cause cancer is unclear, the researchers said, but they noted that other research has linked abnormal cell changes and the body's response to infection.
In the editorial, Zenilman called the study intriguing but not conclusive since there may have been other behavioral or biological factors that contributed to the cancer risk. Still, Zenilman said, the findings may provide another reason to expand screening for chlamydia.
Bacteria Proving Resistant to Drugs
by LINDA A. JOHNSON
A sometimes-lethal type of bacteria that causes many cases of pneumonia, bloodstream infections and other illnesses is rapidly becoming resistant to antibiotics, a government study found.
Experts have warned for a decade that overuse of antibiotics is helping germs become resistant to drugs, first to penicillin, then to newer antibiotics, raising the specter of more deaths and amputations.
''It's become even more worrisome in the last two years,'' said Dr. Cynthia G. Whitney of the Centers for Disease Control and Prevention. ''There are definitely some strains that are fast learners.''
The CDC study looked at Streptococcus pneumonia, the nation's most common bacterial cause of meningitis, children's ear infections and pneumonia. Also called pneumococcus, it is a frequent cause of bacteremia, a bloodstream infection that kills many elderly people.
Between 1995 and 1998, Whitney and colleagues collected 12,045 blood or other fluid samples from U.S. patients infected with Streptococcus pneumonia. Each sample was tested against antibiotics from nine of the 10 or so classes that fight bacteria, with increasingly strong doses of the antibiotic applied until the bacteria were killed.
Over the three-year span, the percentage of pneumococcus samples resistant to three or more antibiotic classes grew from 9 percent to 14 percent. The percentage resistant to penicillin went from 21 percent to 25 percent.
Resistance was particularly high in children under 5 and in whites, two groups generally receiving more antibiotics than others, as well as in parts of the South.
However, the researchers noted that new vaccines, including one approved recently for use in babies, can protect against most drug-resistant strains of the bacteria. Also, a few new antibiotics have been coming onto the market in recent years, and 19 more are in development and could go on sale over the next eight years.
In fact, the researchers found that as newer antibiotics came into greater use, the prevalence of pneumococcus resistant to the older antibiotics decreased.
''It gives us hope maybe we can reverse this trend,'' Whitney said.
The research was reported in Thursday's New England Journal of Medicine.
In an editorial, Drs. Richard P. Wenzel and Michael B. Edmond of Virginia Commonwealth University said that the rise of drug resistance ''should cause great concern and incite a commitment to act responsibly.''
''The antibiotic era is barely 60 years old, yet the inappropriate use of these drugs threatens our ability to cope with infections,'' they said.
Possible Alzheimer Vaccine Found
by MALCOLM RITTER
Taking what could be an important step toward preventing Alzheimer's, scientists found that an experimental vaccine can largely ward off memory loss in mice stricken with a similar disease.
The vaccine is already being tested in people.
''This potentially could be a major breakthrough for us,'' said Zaven Khachaturian, senior science adviser to the Alzheimer's Association.
But he stressed that treatments that work in mice do not necessarily help people and that the mouse research did not deal with some key mental abilities lost in Alzheimer's, such as language and judgment.
The vaccine made headlines last year when scientists reported that it largely blocks the formation of protein deposits called amyloid plaques in the brains of mice. Such plaques are a hallmark of Alzheimer's.
But the next step was to find whether the vaccine makes any difference in the animals' mental functioning.
Two studies published in Thursday's issue of the journal Nature found that the vaccine does indeed make a difference.
The research was conducted by two independent research teams, centered at the University of South Florida in Tampa and the University of Toronto in Ontario, Canada.
The studies used strains of mice that develop lots of amyloid plaques in their brains, along with measurable memory deficits, because of the genes they carry.
The researchers used different versions of a procedure in which mice swam until they learned the location of an underwater platform. The animals were then tested to see how well they remembered where the platform was. Alzheimer's patients frequently have trouble remembering locations and how to get to destinations.
Both studies found that mice that had been repeatedly vaccinated performed markedly better than the untreated plaque-forming mice in the memory tests. On some occasions they did as well or nearly as well as ordinary mice.
University of South Florida researcher Dave Morgan said his vaccinated mice were slower to learn the platform location but eventually remembered it as well as ordinary mice did.
This past July, drug company scientists announced that preliminary results in human patients indicated the vaccine was safe. Those tests were not designed to assess any effect on symptoms.
Human tests are continuing under the sponsorship of Elan Corp. of Dublin, Ireland, and American Home Products Corp. of Madison, N.J. Neither company paid for the new mouse studies.
The researchers who carried out the mouse studies said it is not clear why the vaccine protects memory. For one thing, the research does not settle the question of whether the plaques actually cause the symptoms of Alzheimer's.
The vaccine was designed to make the mouse immune system attack amyloid-beta peptide, also called beta amyloid, a key component of the brain plaques in Alzheimer's. And both studies found that vaccinated mice had fewer and smaller amyloid plaques in their brains.
But Morgan noted that his treated mice still had a lot of plaques.
He and Dr. Peter St George-Hyslop, one of the University of Toronto researchers, suggested the vaccine might act on a harmful form of amyloid-beta peptide outside of the plaques.
Light to Moderate Alcohol Consumption Linked With Fewer Strokes in Young Women
WESTPORT, CT (Reuters Health) Jan 04 - Women 15 to 44 years of age who drink up to two alcoholic drinks per day, particularly wine, have fewer ischemic strokes compared with young women who never drink alcohol, according to a report in the January issue of Stroke.
Dr. Ann M. Malarcher from the Centers for Disease Control and Prevention in Atlanta and colleagues collected data on 224 young US women after their first cerebral infarction and on 392 age-matched controls. The subjects were asked about their lifetime alcohol consumption and type of alcohol consumed during the past year, week and day.
The researchers found that compared with women who never drank alcohol, women who drank fewer than 12 grams of alcohol per day had a lower risk of ischemic stroke (odds ratio 0.57), as did those who consumed 12 to 24 grams per day (odds ratio 0.38). For those who drank more than 24 grams per day, the odds ratio for stroke was comparable to that of nondrinkers.
"Women who drank in the past week, and whose average intake for the week was two alcoholic drinks a day, had an almost 60% lower stroke risk than those who never drank," Dr. Malarcher commented in a journal statement. "Wine appeared to have a beneficial effect, while beer and liquor were not as strongly related to stroke risk."
"Findings from this study indicate," the researchers conclude, "that the National Stroke Association's Prevention Guidelines on alcohol use apply to young adults: drinking in moderation (up to 2 drinks per day) can be recommended for those who drink alcohol and who have no health contraindications."
However, the researchers also point out that "alcohol use should not be encouraged for those who do not already drink."
WESTPORT, CT (Reuters Health) Jan 04 - Increased glycated hemoglobin (HbA1c) concentrations are predictive of cardiovascular mortality among all men, not only those with diabetes, according to a report in the British Medical Journal for January 6.
Dr. Kay-Tee Khaw and colleagues, from the University of Cambridge School of Clinical Medicine, UK, collected data on all-cause mortality and cardiovascular mortality in 4662 men, 45 to 79 years of age, who participated in the Norfolk UK cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk). At baseline, from 1995 to 1997, HbA1c was measured and the subjects were followed until December 1999.
As expected, Dr. Khaw's group found that diabetic men had increased mortality for all causes, cardiovascular disease and ischemic disease. They also noted that HbA1c concentrations were "continuously related to subsequent all-cause, cardiovascular, and ischemic mortality through the whole population." The lowest mortality rates were associated with HbA1c concentrations below 5%.
Further, the group noted that a 1% increase in HbA1c was associated with a 28% increased risk of death, which was independent of age, blood pressure, cholesterol, body mass index and smoking.
"Eighteen percent of the population excess mortality risk associated with a HbA1c concentration of 5% or more occurred in men with diabetes, but 82% occurred in men with concentrations of 5% to 6.9% (the majority of the population)," Dr. Khaw and colleagues point out.
The researchers propose that an elevated concentrations of HbA1c is a marker for greater absolute risk among all men, and "preventive treatment with blood pressure- or cholesterol-lowering drugs should be considered in such patients."
They point out that if the population of nondiabetic men was able to lower its HbA1c concentration by 0.1%, total mortality could be reduced by 5%, and if the concentration could be lowered by 0.2%, then total mortality could be reduced by 10% in this population.
Reducing Dietary Salt Significantly Lowers Blood Pressure in Virtually All Subjects
WESTPORT, CT (Reuters Health) Jan 03 - A low-salt diet or the DASH (Dietary Approaches to Stop Hypertension) diet significantly lowers blood pressure in both hypertensive and normotensive subjects, according to a report in the New England Journal of Medicine for January 4.
"Almost everybody agrees that salt reduction is useful for people with hypertension and this study shows that salt reduction has a major effect on blood pressure, more than one might have expected," Dr. Frank M. Sacks from the Harvard School of Public Health told Reuters Health.
There is a controversy about the effect of salt in nonhypertensives, which was fueled by small-scale studies that came up with divergent findings, Dr. Sacks noted. "That's why we went into a big study with complete dietary control to really settle the issue one way or the other," he said.
Dr. Sacks and colleagues from the DASH-Sodium Collaborative Research Group studied 412 subjects who were randomly assigned to eat either a controlled diet, which was typical of a normal US diet, or the DASH diet, which is rich in fruits, vegetables and low-fat dairy. Within each dietary group, subjects ate foods with a high, intermediate and low level of salt for 30 days.
"We tested a mix of subjects," Dr. Sacks added. "They all had to have blood pressure higher than 120/80 mm Hg, and 41% were hypertensive, with systolic blood pressures between 140 and 160 mm Hg."
The researchers found that reducing sodium intake from the high (150 mmol/d) to the intermediate (100 mmol/d) level resulted in a decrease in mean systolic blood pressure of 2.1 mm Hg among those on the control diet and a mean of 1.3 mm Hg for those on the DASH diet. When salt was reduced to the lowest level (target 50 mmol/d) there was an additional reduction in systolic pressure of a mean of 4.6 mm Hg among those receiving the control diet and a mean of 1.7 mm Hg for those on the DASH diet.
"The effects of sodium were observed in participants with and those without hypertension, blacks and those of other races, and women and men," the investigators write. In addition they point out that compared with the high-sodium control diet, the low-sodium DASH diet resulted in a mean reduction in systolic blood pressure of 7.1 mm Hg among nonhypertensives and 11.5 mm Hg among hypertensive subjects.
"Our group recommends that people reduce their salt intake. For hypertensive patients salt reduction is clearly very important, as is the DASH diet," Dr. Sacks commented.
"Initial treatment for hypertension should be nutritional," he continued. "The effect of salt reduction from the recommended 100 millimoles per day to 60 millimoles per day or the effect of the DASH diet or the combination gives you the same if not better results than initial drug therapy. And if a patient is already on drug therapy and follows this diet they have a good chance of reducing their medication or even eliminating the need for it," Dr. Sacks stressed.
"The main message of this new trial...is that the results appear to be applicable to most people in the US," Dr. Philip Greenland, from Northwestern University Medical School, Chicago, comments in a journal editorial. He goes on to say that "the widespread adoption by all persons, with or without hypertension, of sound dietary guidelines, such as those of the American Heart Association, should result in improved control and prevention of hypertension, as well as broad improvement in other measures of health."
N Engl J Med 2001;344:3-10,53-54.
Long-Term Use of Nonaspirin NSAIDs Reduces Colorectal Cancer Risk
WESTPORT, CT (Reuters Health) Jan 03 - Long-term use of nonaspirin nonsteroidal anti-inflammatory drugs (NA-NSAIDs) reduces the risk of colorectal cancer by half, independent of the treatment indication, according to a report in the January issue of Epidemiology.
Researchers conducted a population-based cohort study with secondary case-control analysis to examine the link between colorectal cancer risk and use of aspirin and individual NSAIDs, including the role of dose and duration. Using the General Practice Research Database in the UK, they traced 943,903 subjects who were between the ages of 40 and 79 years and who were free of cancer and colorectal adenoma from 1994 to 1997.
Drs. Luis A. Garcia Rodriguez and Consuelo Huerta-Alvarez, from the Centro Espanol de Investigacion Farmacoepidemiologica, in Madrid, Spain, identified 2002 incident cases of colorectal cancer. "The incidence rate of colorectal cancer per 10,000 person-years was 7.3," they write.
After 6 months of continuous treatment, the risk of colorectal cancer was reduced in people who used NA-NSAIDs, according to the investigators, with an adjusted relative risk of 0.5. "High daily doses were associated with a slightly greater reduction than low-to-medium doses," they note. One year after stopping NSAID treatment, the reduction in risk disappeared completely.
According to the report, long-term users of aspirin at doses of 300 mg/day also had a reduced risk of developing colorectal cancer, with a relative risk of 0.6. However, there was no reduction in risk among those who used aspirin at daily doses of 75 mg and 150 mg.
Based on these findings, "1-year treatment with NSAIDs would prevent one case of colorectal cancer in a population of 1000 persons 70 to 79 years of age," the authors conclude.