New Blood Test Could Make Predicting Heart Trouble More Accurate
LONDON (AP) - A new blood test may permit more accurate predictions of a person's risk of a fatal heart attack, scientists say.
A study published this week in The Lancet medical journal suggested the test, which measures levels of the protein part of cholesterol, may be a better predictor of heart trouble than traditional cholesterol tests and may one day lead to more tailored treatments.
High cholesterol is considered one of the strongest risk factors for developing coronary artery disease and dying from a heart attack, but some people develop heart trouble despite apparently normal levels of HDL and LDL cholesterol.
Experts say the new test, which involves measuring levels of cholesterol components called
apolipoproteins, will fine-tune traditional cholesterol testing.
Apolipoprotein A-1, or apoA-1, is the protein part of HDL, the good cholesterol, while apolipoprotein B, or apoB is the protein in LDL, the bad cholesterol.
In the study, led by drug company Astra Zeneca scientist Dr. Goran
Walldius, researchers measured the blood concentration of the apolipoproteins as well as the traditional triglycerides, total cholesterol and LDL cholesterol in 175,553 Swedish people and followed them for, on average, five and a half years.
By the end of the study 864 men and 359 women had died of a heart attack.
The steepest increase in risk of heart attack related to cholesterol protein levels was seen when comparing those with the worst profiles with those with the best.
Men who had the highest levels of apoB, the bad protein, combined with the lowest levels of apoA-1, the good protein, were nearly four times more likely to suffer a fatal heart attack than those who had the lowest concentrations of the bad protein and the highest of the good protein. A similar pattern was seen for women, the study found.
The researchers found that measuring levels of apoB, attached to the bad LDL cholesterol, predicted fatal heart attacks more accurately than simply measuring LDL.
ApoA-1, the good cholesterol protein, seemed to protect against heart attacks.
Also, the higher the ratio of bad protein to good protein, the more likely someone was to later die of a heart attack.
"This is perhaps the largest study to date demonstrating that the ratio of apoB to apoA-1 may offer better predictive value for the development of coronary disease than most other data we commonly track," said Dr. David A.
Meyerson, a Johns Hopkins University cardiologist and American Heart Association expert who was not connected with the study.
"We may now be at the threshold where this should be a routine measurement," he said.
The researchers noted a few apparent advantages of the new test. It was good at predicting later fatal heart attacks in people whose cholesterol tests were normal. Also, it worked just as well in young as old people. Traditional cholesterol tests are not found to be useful for people over 70.
The apolipoproteins could also eventually become the target of new drugs, experts say.
Scientists do not yet know what level of apolipoproteins should be considered normal or health, at what point patients should be given drugs to improve their profiles, nor to what concentration drugs should bring the proteins to.
"Studies need to be done on whether treatments aimed at changing the apolipoprotein levels will work better at preventing the progression of heart disease than our current drugs," Meyerson said.
Surgeon General: Obesity Rates at Epidemic Levels (Dec.
WASHINGTON (Reuters Health) - The poor diets and sedentary lifestyles that have become a hallmark of American culture are causing rapidly rising obesity rates that are threatening America's health, Surgeon General Dr. David Satcher said on Thursday.
Dr. Satcher issued a report calling on individuals, families, schools, and businesses to take steps to help children and adults lose weight and lead healthier lifestyles. A staggering 61% of American adults currently meet the medical definition of overweight or obese, putting them at increased risk of heart disease, diabetes, stroke, arthritis, depression, and several forms of cancer.
Since the late 1970s, obesity rates have gone up 30% among US adults. Meanwhile, just one third of US adults meet recommendations for at least 30 minutes of exercise 5 days per week.
"This is probably the most sedentary generation of people in the history of the world," Dr. Satcher said.
Dr. Satcher, whose term ends this February, asked Americans to avoid fad diets and focus on healthy eating habits and regular exercise. However, few Americans come close to eating the types and portions of foods recommended on "food pyramids."
"We're talking about choices. We're talking about balance. We're not talking about quick-fix diets," he said.
Figures from the Centers for Disease Control and Prevention show that 43% of US high school students spend 2 hours per day or more watching television. Overweight and obesity rates have tripled since the late 1970s and now run as high as 14% in US children as a whole. Rates are even higher in African-American and Hispanic communities.
"Our school system must bear some of the blame," said Dr. Satcher, who noted that only Illinois requires physical education classes for all K-12 students. Schools should move to promote low-fat, healthy food in lunches and minimize the presence of vending machines on school grounds, he said.
Dr. Satcher also asked businesses to promote healthier workplaces by promoting exercise among employees and encouraging breastfeeding among lactating mothers.
Secretary of Health and Human Services Tommy G. Thompson cited studies indicating that that losing just 15 pounds can cut the risk of developing type 2 diabetes by nearly 60%. Such reductions could save the US health system as much as $58 billion per year, he said.
Genetically Influenced Asthma Onset Greater in Sedentary Women (Dec
NEW YORK (Reuters Health) - Polymorphisms of the beta2-adrenoceptor genes appear to have an association with adult-onset asthma in sedentary, but not in active women, according to researchers at the Harvard Medical School in Boston and at other centers.
Dr. R Graham Barr and colleagues note that a "sedentary lifestyle is associated with adult-onset asthma." Furthermore, Glu27 polymorphism of the beta2-adrenoceptor may predict body mass index (BMI). Gly16 polymorphism is also associated with asthma severity.
The researchers therefore hypothesized that "these DNA sequence variants predict adult-onset asthma only in sedentary women." To investigate, they studied 171 women with adult-onset asthma requiring medication, and 137-age matched controls. None of the subjects had ever smoked. The findings appeared in the November issue of Chest.
Overall, neither the presence of Gly16 alone or in combination with Glu27 predicted the occurrence of asthma. However in the 76 women with a self-reported sedentary lifestyle, the adjusted odds ratio for the Gly16 allele were 7.4 for asthma and 13.8 for asthma requiring steroid treatment. No such associations were seen in the physically active women.
BMI was associated with asthma and the Glu27 allele in sedentary women. The risk of asthma was less elevated in sedentary women with both alleles.
Commenting on this preliminary finding, lead author Dr. R. Graham Barr told Reuters Health that "if confirmed, it would suggest that certain variants of beta-receptor genes predispose to asthma, but only among people who are sedentary."
This would be important, he added, "because it suggests that underlying predilection to asthma may be unmasked by sedentary lifestyle — a phenomenon increasing in our society."
In an accompanying editorial, Dr. R. Andrew McIvor of Dalhousie University, Halifax, Nova Scotia, Canada, agrees, pointing out that "even though this study design is only hypothesis-generating, it may suggest a very important public health message."
In those with asthma and their family members, he concludes, "we should encourage frequent exercise in accordance with their capabilities, physical limitations and personal interests."
Air Travel May Be Safe for Women in Last Trimester
NEW YORK (Reuters Health) - Women who are in the late stages of pregnancy may still be able to safely travel by air, according to new guidelines released on Wednesday by the American College of Obstetricians and Gynecologists (ACOG). Pregnant women can also exercise more than previously recommended, the group said.
"Pregnancy should not be a state of confinement," Dr. Raul Artal of St. Louis University School of Medicine in Missouri told Reuters Health. He announced the new guidelines during ACOG's press briefing on the latest controversies in obstetrics.
Until now, there were no formal recommendations on flying during pregnancy, Dr. Artal noted. Most airlines in the United States allow women to travel until they are about 9 months pregnant, but international airlines prohibit women from flying after 35 weeks of pregnancy, according to an ACOG statement.
ACOG's new guideline states that "in the absence of medical or obstetric complications, air travel is safe up to 36 weeks," Dr. Artal said.
Women who are at risk for preterm delivery, those with poorly controlled diabetes, and those with placental abnormalities, however, are advised to refrain from air travel while pregnant.
Some women, particularly those with heart problems, may experience discomfort while flying due to changes in cabin pressure, which may lead to subsequent increases in both their heart rate and blood pressure. Those at risk for such problems "should be prescribed supplemental oxygen during air travel," according to ACOG women's health experts.
In addition, pregnant women should avoid consuming beans, sodas and other gas-producing foods or drinks before flying, and should wear support stockings to prevent any fluid from accumulating in their legs.
Like all other airline passengers, pregnant women are advised to move their legs periodically during their flight to prevent blood clots.
In a separate announcement during Wednesday's briefing, ACOG also indicated that pregnant women should no longer limit their exercise as previously recommended, but should engage in 30 minutes of daily moderate exercise to gain maximum health and heart benefits.
Furthermore, women should no longer be discouraged from beginning exercising during pregnancy, Dr. Artal noted.
"For women that have never engaged in exercise, pregnancy may not be a bad time to start thinking about it," he said. He added that pregnant women should exercise in moderation and should take the necessary precautions.
The ACOG guidelines on exercise will be released in January, Dr. Artal said
High Isoflavone Intake Increases BMD in Postmenopausal Women(Dec.13,
NEW YORK, (Reuters Health) - Postmenopausal women with a high intake of dietary isoflavone have higher bone mineral density (BMD) than women whose isoflavone intake is low. However, isoflavone intake has no effect on the BMD of premenopausal women, Chinese researchers report.
Dr. Annie W. C. Kung, and colleagues from the University of Hong Kong, collected data for 650 Chinese women between 19 and 86 years of age. The researchers used a food frequency questionnaire to determine the intake of isoflavone. They also measured the women's BMD at the lumbar spine and hip.
After adjusting for age, height, weight, years since menopause, smoking, alcohol intake, hormone replacement therapy use, and daily calcium intake, postmenopausal women who had the highest intake of isoflavone had significantly higher BMD compared with postmenopausal women who had the lowest intake of isoflavone.
Mean BMD at the lumbar spine was 0.820 g/cm2 for postmenopausal women with the highest isoflavone intake compared with 0.771 g/cm2 for those with the lowest isoflavone intake (p < 0.05), the researchers found. This difference was also seen at Ward's triangle (0.450 g/cm2 versus 0.415 g/cm2, p < 0.05).
However, among premenopausal women, with high endogenous estrogen levels, no link between isoflavone intake and BMD was found, according to the report in the November issue of the Journal of Clinical Endocrinology and Metabolism.
Dr. Kung and colleagues conclude that "customary high isoflavone intake may help to reserve the state of secondary hyperparathyroidism associated with estrogen withdrawal and, hence, lower the rate of bone turnover in postmenopausal women."
J Clin Endrocrinol Metab 2001;86:5217-5221
Prepregnancy Waiting Time After Rubella Vaccine Shortened
(Dec. 13, 2001)
ATLANTA (Reuters Health) - The recommended waiting period before becoming pregnant after a rubella vaccination has been decreased from 3 months to 28 days, according to researchers at the US Centers for Disease Control and Prevention (CDC).
The CDC announced the change made by the CDC's Advisory Committee on Immunization Practices (ACIP) in the December 14th issue of the agency's Morbidity and Mortality Weekly Report.
According to Dr. Sue Reef with the CDC's National Immunization Program, the recommendation, now 28 days, has been at 3 months since 1977.
"I think this is a very important change, because many people may be hesitant to get the vaccination at all if they have to wait such a long period of time before getting pregnant," she told Reuters Health.
ACIP made the change on October 18 after various data indicated that that "no cases of congenital rubella syndrome had been identified among infants born to women who were vaccinated inadvertently against rubella within 3 months or early in pregnancy."
But a theoretical risk cannot be ruled out, they note. When the CDC limited the analysis to the 293 infants born to susceptible mothers vaccinated 1 to 2 weeks before and 4 to 6 weeks after conception, the maximum theoretical risk was 1.3%.
Compared with a greater than 20% risk of congenital rubella syndrome associated with maternal infection during the first 20 weeks of pregnancy, "this risk is substantially less," they note.
According to the CDC, clinicians should counsel women to avoid becoming pregnant for 28 days after vaccination the MMR or other rubella-containing vaccines. The MMR vaccine and its component vaccines should not be administered to women known to be pregnant, they point out.
According to the CDC, most rubella cases in the US occur among young Hispanic adults born outside the country, and most infants with congenital rubella syndrome are born to foreign-born mothers.
"Ensuring immunity in women of childbearing age, especially those at highest risk for exposure, will help to prevent congenital rubella syndrome," they note
Supplemental Calorie Intake May Ameliorate Exercised-Induced Amenorrhea
NEW YORK (Reuters Health) - Women with exercised-induced amenorrhea may be able to reverse the condition by adding more calories to their diet, according to preliminary findings from an animal model.
"Our goal was to understand whether reproductive dysfunction due to high levels of exercise was due to the stress of exercising or to the amount of energy that gets used during exercise," Dr. Judy L. Cameron from the University of Pittsburgh, told Reuters Health. "The findings show that it is energy consumption during exercise that causes reproductive dysfunction," she said.
Dr. Cameron and colleagues trained eight female adult monkeys to exercise on a treadmill. Over 7-to-24 months, the researchers increased the exercise program until the monkeys developed amenorrhea.
The monkeys underwent rigorous exercise training comparable to that used by humans. The animals started by walking and slowly increased activity until they were running at levels similar to whose used by humans in marathon training, Dr. Cameron explained.
During the initial part of the training, food intake remained the same, according to the report in the November issue of the Journal of Clinical Endocrinology and Metabolism.
While four of the monkeys remained on the standard diet, the other four were given supplemental calories while the exercise program continued. All four monkeys that received extra calories showed increased hormone levels and reestablished ovulatory cycles. Recovery from amenorrhea was directly related to the amount of extra calories the monkeys ingested (p < 0.05), the researchers found.
As amenorrhea developed, there was a 27% decrease in plasma T3 levels which significantly increased (18%; p < 0.05) as amenorrhea was reversed, Dr. Cameron's team notes.
"From a treatment point of view, the implication is fantastic," Dr. Cameron said. One can restore reproductive function that is lost as a result of intense exercise by taking in a few more calories.
Many Postmenopausal Women Have Undiagnosed Low BMD
(Dec. 11, 2001)
NEW YORK (Reuters Health) - The results of a large US population-based study show that almost half of postmenopausal women have undiagnosed low bone mineral density (BMD), putting them at high risk of osteoporosis, osteopenia, and fractures.
"In the primary care setting women are not routinely being evaluated for the risk of osteoporosis," Dr. Ethel S. Siris from Columbia Presbyterian Medical Center, New York, told Reuters Health. "We found that 46% of real world women had low BMD or osteoporosis," she added.
Dr. Siris and colleagues collected data for 200,160 postmenopausal women 50 years of age or older, with no history of osteoporosis, who were seen in 4236 primary care practices in the US. The participants were enrolled in the National Osteoporosis Risk Assessment (NORA) study.
The study was started in 1997 and continued into 1999, with approximately 12 months of additional follow-up, according to the report in The Journal of the American Medical Association for December 12.
The researchers obtained BMD T scores and at the heel, finger or forearm. A BMD T score of 0 equals the mean peak BMD of a healthy population of premenopausal white women between the ages of 20 and 29 years, the researchers explain. Using a questionnaire, at baseline and after 12 months, they determined risk factors for low BMD and fracture rates.
Among the 163,979 women who provided follow-up data, 39.6% were diagnosed with osteopenia and 7.2% with osteoporosis. "I didn't think we were going to find that nearly half the women had low bone density," Dr. Siris said. This is probably an underestimate, she noted, because women already diagnosed with osteoporosis were excluded from the study.
Factors that made developing osteoporosis significantly more likely included age, personal or family history of fracture, being Asian or Hispanic, smoking, and using cortisone, the researchers found.
Having a high body mass index, being African-American, using estrogen or diuretics, regular exercise, and consuming alcohol were all associated with a significantly lower osteoporosis risk, Dr. Siris' team reports.
Women with osteoporosis had a fracture rate almost 4-fold greater than women with normal BMD (rate ratio 4.03) and women with osteopenia had a fracture rate 1.8-fold higher than women with normal BMD, the investigators add.
"There is a lot of low bone density out there in this population at risk," Dr. Siris said. "We need to get into a preventive mode to minimize the number of fractures we currently see," Dr. Siris said.
The NORA findings confirm "what many clinicians and osteoporosis researchers have long suspected, ie, that a significant number of postmenopausal women in primary care practices have clinically significant low BMD and that such women have increased risk of incident fracture within 1 year," Dr. Charles H. Chesnut III from the University of Washington Medical Center, Seattle, comments in a journal editorial.
"Based on the current study, strategies to identify, manage, and treat osteoporosis in primary care need to be established and implemented 51; hopefully, sooner rather than later."
Diet May Mask Eating Disorder in Teens (Dec
NEW YORK (Reuters Health) - Teenage vegetarians may be
at greater risk of eating disorders and suicide than their meat-eating peers,
according to researchers.
Their study found that adolescent vegetarians were more weight- and
body-conscious, more likely to have been told by a doctor that they had an
eating disorder, and more likely to have tried a variety of healthy and
unhealthy weight control practices including diet pills, laxatives and vomiting.
They were also more likely than their peers to have contemplated or attempted
Male vegetarians were even more likely to engage in unhealthy weight control
practices, such as vomiting after eating and weighing themselves frequently,
than were non-vegetarian males, report researchers in the December issue of the
Journal of Adolescent Health.
The findings suggest that vegetarianism may serve as a red flag for eating and
other problems related to self-image in teens, conclude Dr. Cheryl L. Perry,
from the University of Minnesota, and colleagues.
"Our study indicates that adolescent vegetarians are more likely than adult
vegetarians to be vegetarians for weight-control than for health reasons.
Because they are so interested in weight control, they engage in a variety of
behaviors that are associated with trying to lose weight, both healthy and
unhealthy," Dr. Perry explained in an interview with Reuters Health.
The study found that nearly 6% of nearly 5000 urban middle- and high-school
students surveyed in Minnesota reported that they were vegetarian or did not eat
red meat. More than half of the vegetarians reported eating chicken, about 42%
ate fish, more than 75% ate eggs and nearly 80% consumed dairy products.
Overall, semi-vegetarians, or those who ate some animal products, were more
likely to engage in weight-control practices but less likely to exercise than
restricted vegetarians. Semi-vegetarians, the authors suggest, may be using the
diet as another form of weight control and may be a target for programs to
prevent eating disorders.
All vegetarians weighed themselves more often and were more likely to say that
they were dissatisfied with their bodies than were non-vegetarians. Vegetarians
were also more likely to report that they cared less about being healthy
although they cared more about eating healthy foods.
The results of the study show that nearly 75% of vegetarians were females and
nearly half were white. The main reason for following a vegetarian diet was a
desire to lose or maintain weight. Students also said they did not want to be
involved in killing animals, they did not like the taste of meat, they thought
vegetarianism was a healthier diet, and they wanted to help the environment.
A vegetarian diet can be more healthy than one that contains red meat, the
authors note. Studies have found that adult vegetarians tend to live longer, are
generally leaner and are less likely to be diagnosed with heart disease and some
cancers than adults who consume animal products.
"Although adult vegetarianism has demonstrated healthful outcome,
adolescent vegetarianism may be a signal that other, health-compromising
attitudes and behaviors may also be adopted, particularly those related to
unhealthy weight control," the study authors conclude.
Can Safely Remove Large Volumes of Fat (Dec
NEW YORK (Reuters Health) - Certain patients who are slightly
overweight to moderately obese can safely have the equivalent of up to 17 liters
(about 4.5 gallons) of fat suctioned from their body in a single operation,
Large-volume liposuction had been previously associated with dangerous
complications, such as excessive blood loss requiring blood transfusions. Other
safety concerns include pulmonary edema.
But a new approach known as the "superwet" technique, in which
surgeons inject fluids containing local anesthetic and vasoconstricting agents
into fat prior to surgery, can reduce blood loss significantly, and is
associated with an extremely low rate of complications.
For instance, before the superwet technique was adopted in the early 1990s,
about 70% fat and 30% blood was removed, according to the report in the November
issue of Plastic and Reconstructive Surgery. Now, the average mass contains 1%
blood, 70% fat and 29% crystalloid solution.
"Advances in the understanding of physiology during liposuction and
advances in surgical and anesthetic techniques have allowed greater and greater
volumes to be removed at one setting," Dr. George W. Commons and colleagues
from Stanford University in Palo Alto, California, conclude.
The findings are based on a review of 631 patients who underwent large-volume
liposuction, performed by Dr. Commons, over 12 years. All patients had at least
3 liters of fat removed and the majority of patients had up to 10 liters of fat
removed. Most patients (93%) were women and nearly all weighed within 50 pounds
of their ideal weight, according to medical charts.
One year after surgery, about 80% of patients had maintained their postoperative
weight. The majority of complications were minor, including skin injuries and
burns and allergic reactions, but 4 patients (0.6%) developed mild pulmonary
edema and 1 patient developed pneumonia. None of the patients required a blood
transfusion or died from the surgery.
"The results show that large-volume liposuction can be a safe and effective
procedure when patients are carefully selected and when anesthetic and surgical
techniques are properly performed," Dr. Commons and colleagues conclude.
In an accompanying editorial, physicians from the University of Texas
Southwestern Medical School in Dallas stress that liposuction is a procedure for
patients who are healthy. Individuals with underlying medical problems or those
who are obese are not candidates for the procedure, as Dr. Commons and
colleagues make clear by their selection of patients, they note.
"Aside from being in good general health, patients must also have realistic
expectations and be motivated to make necessary changes such as diet, exercise,
and lifestyle alterations," write Dr. Rod J. Rohrich and colleagues.
Smoking Cessation Can Markedly Reduce Small-Cell Lung Cancer Risk
NEW YORK (Reuters Health)
- Smoking cessation effectively reduces the risk of lung cancer in both men and women, according to a report in the November issue of Chest. This effect is significantly greater for small cell lung carcinoma (SCLC) and squamous cell carcinoma
(SQC) and is most marked in women and in heavy smokers.
In a meta-analysis of peer-reviewed studies, Drs. Sadik A. Khuder and Anand B.
Mutgi, of the Medical College of Ohio, Toledo, examined the effect of smoking cessation on rates of major histological types of lung cancer. They calculated combined estimates of relative risk for 27 case-control and 1 prospective cohort studies published between 1970 and 1999, and conducted separate analyses for men and women.
The researchers found an association between smoking cessation and a reduction in the risk of all major histological types of lung cancer. "The highest reduction was in SCLC and
SQC, and the lowest reduction was seen in large cell cancer and
adenocarcinoma," they explain.
The physicians note that as the number of years of abstinence from smoking increased, the odds ratio decreased progressively. This was true for all types of lung cancer.
The combined risks for SCLC and SQC were higher in women than in men, the investigators report. In addition, "the dose-response curve for intensity of smoking was steeper in women."
"This finding is clinically significant, as SCLC incidence appears to be increasing more rapidly in women than in men," Drs. Khuder and Mutgi point out. "Increased efforts toward smoking cessation in women would yield earlier and greater reductions in SCLC."
Zinc Helps Low Birth Weight Babies
(Dec. 10, 2001)
(Ivanhoe Newswire) — Zinc may be the key to improving mortality rates of infants in developing countries, according to a new study. Johns Hopkins University researchers find zinc could provide a substantial reduction in infectious diseases in low birth weight babies.
Researchers studied more than 1,100 full-term infants considered smaller than average. Infants were separated into four groups. Each group received doses of different minerals and supplements. One group received riboflavin while a second group received riboflavin and zinc. A third group received riboflavin, calcium, phosphorous, folate and iron and the final group received riboflavin, calcium, phosphorous, folate, iron and zinc. The supplements were given to each child every day for one to nine months. Infants were also visited daily to assess any illness or death.
Recent research has shown low birth weight infants have low zinc concentrations in their cord blood. In the study researchers report zinc supplementation was associated with a significantly lower mortality rate. They also found the calcium, phosphorous, folate and iron supplementation was not associated with a reduction in death.
Researchers say zinc deficiency found in these low birth weight infants can result in severe diarrhea, which can lead to death. They add the potential to improve zinc supplementation in these infants and reduce the number of infants dying is very important for child survival in developing countries.