Allegra

Low levels of physical activity in young adults may account for a “substantial” proportion of high blood pressure incidence over time, researchers report in Hypertension: Journal of the American Heart Association.

The 20-year observational study, conducted by scientists at Northwestern University Feinberg School of Medicine in Chicago, Ill., involved 4,618 white and African-American men and women taking part in the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

“High blood pressure is known to develop over many years and is due to many factors including diet, health behaviors and genetics,” said Mercedes Carnethon, Ph.D., study lead author and assistant professor of preventive medicine at Feinberg. “Our study measures a comprehensive set of these health risk factors over 20 years — making this one of the longest follow-up studies to test whether activity and fitness are associated with hypertension development.”

The study confirms and extends earlier findings that linked fitness and hypertension “by showing that fitness during young adulthood — a time when cardiovascular disease risk factor burden is typically low — is an important indicator of hypertension development in middle age,” Carnethon said.

Low fitness has a stronger association with the development of hypertension than low self-reported physical activity, yet the two appear to have independent effects, researchers said. Fitness is a precise measure obtained from treadmill duration testing. Activity was assessed with an interviewer administrated self-reported questionnaire and thus imprecise, but is associated with hypertension development, researchers said.

The researchers measured blood pressure and estimated fitness levels based on the duration of exercise treadmill tests conducted in young adults 18 to 30 years old in 1985. The participants were re-examined after two, five, seven, 10, 15 and 20 years.

Researchers found:

· Hypertension incidence (blood pressure over 140/90 millimeters of mercury) was 13.8 per 1,000 person-years (this information was found by taking the number of new cases within a specified time period divided by the size of the population initially at risk).

· Low fitness was significantly associated with the increased risk of developing hypertension with each tertile (third) of increased physical activity after adjusting for smoking, age, sex, race, cholesterol, diet and other factors.

· The “preventive fraction,” the estimated proportion of hypertension that could be prevented if participants moved to a higher fitness category, was 34 percent and varied by race and sex (preventive fraction is a measure of the public health burden of disease).

“Preventive fraction tells us, hypothetically, what proportion of disease could be eliminated if the risk factor was removed from the population,” Carnethon said.

One of the study’s important findings is the role of race and gender.

Although a larger proportion of black participants and men develop hypertension over 20 years, fitness and physical activity play a similar role in the development of hypertension in black or white women and men, researchers said. “There’s no evidence from our study that activity or fitness recommendations for hypertension prevention should be different by sex or race,” Carnethon said, adding that clinical trials should test activity prescriptions in all adults.

The study’s primary limitation is that it cannot lead to a recommendation about the amount of physical activity needed to improve fitness and to lower the risk of developing hypertension, Carnethon said. So clinical trials are needed to manipulate activity and fitness.

“In an observational study, we cannot specifically address whether high activity and fitness can actually prevent hypertension,” she said. “We can only discuss the associations of health behaviors and physical traits, i.e., fitness and hypertension development.”

Co-authors are: Natalie Evans, M.D.; Timothy Church, M.D., M.P.H., Ph.D.; Cora Lewis, M.D.; Pamela Schreiner, Ph.D.; David Jacobs, Jr., Ph.D.; Barbara Sternfeld, Ph.D.; and Stephen Sidney, M.D., M.P.H.

The National Heart, Lung, and Blood Institute funded the study.

The way buildings, neighborhoods, and cities are designed can affect your health. Read how CDC works with city and transportation planners and architects to help them consider the health effects of their projects and policies.

Designing buildings and communities in a way that protects people’s health is possible when the right people work together, according to a new report from the Centers for Disease Control and Prevention (CDC).

The report is from CDC’s Healthy Community Design Initiative expert workshop [PDF - 394 KB],
held in Atlanta in September 2009. The workshop convened experts from academia, architecture, building, development, government, planning, and public health to consider the effect that community design has on health. The report [PDF - 394 KB] recommends action steps to
advance healthy community design principles. Scientists and developers who met at the workshop believe that building neighborhoods and buildings to enhance physical activity, respiratory health, mental health, water quality and social capital can lead to reduced asthma, diabetes, and obesity, and improve residents’ quality of life.

“We recognized that a common concern over health exists, but common language among disciplines is lacking,” said Dr. Andrew Dannenberg, who leads CDC’s Healthy Community Design Initiative. “And, although we share the same concerns about health, different disciplines (were) not working together to address them.”

In addition to convening the Healthy Community Design Initiative workshop, CDC participates in other efforts to support a healthy built environment. For example, CDC worked closely with the Congress for the New Urbanism (CNU) on CNU’s May 2010 conference, “New Urbanism: Rx for Healthy Places,” held in Atlanta. Health professionals, planners, developers, and policy makers at every level discussed how to ensure that health is considered in code reform, transportation, neighborhood design, and public space initiatives.

Dr. Dannenberg said these efforts will lead to better communication and healthier planning practices. “CDC is working to foster collaboration and help establish a practice of considering health effects when making land use, transportation planning, and other community design decisions,” he said.

National Institutes of Health scientists have discovered that the activation of immune cells called basophils causes kidney damage in a mouse model of lupus nephritis. These findings and the team’s associated research in humans may lead to new treatments for this serious disease, a severe form of systemic lupus erythematosus (SLE) that affects the kidneys and is difficult to treat.

In earlier research, the team found that mice engineered to be deficient in a protein called Lyn kinase had exaggerated responses to allergens in early life and developed a lupus-nephritis-like disease in later life. This was determined by monitoring the increase of immunoglobulin E (IgE) responses to normally harmless substances. The new study, published online in Nature Medicine, demonstrates for the first time, in the context of this mouse model, how basophils activated by self-reactive IgE antibodies (antibodies that attack the self instead of germs) might contribute to the kidney damage associated with SLE.

Specifically, the team showed that self-reactive IgEs attached to the surface of basophils, causing them to home to the mouse’s spleen and lymph nodes, where they promoted a cascade of cellular events that enhanced the production of more self-reactive antibodies. These antibodies are already known to cause kidney damage by binding with other proteins to form immune complexes that are deposited in the kidneys. Here, they caused inflammation, damage and progressive loss of kidney function.

Furthermore, the scientists demonstrated that inducing the absence of self-reactive IgEs or depleting the population of basophils relieved many of the kidney disease features seen in the mouse model.

To explore the implications of their results in humans, the scientists examined blood samples from 44 people with SLE and found the presence of self-reactive IgEs, as well as an increase in activated basophils, features not seen in healthy controls. Both factors were strongly associated with disease activity and lupus nephritis in the people with SLE, suggesting a potential therapeutic benefit in reducing the levels of self-reactive IgE or of activated basophils.

One such potential treatment, the asthma medicine omalizumab, is already on the market. It blocks IgE from binding to the surface, and potential activation, of basophil cells, which might prevent basophils from promoting kidney inflammation. The NIH team is currently planning a safety study of omalizumab in people with SLE.

“We are excited by the potential of these findings in the treatment of lupus. Obviously, whether omalizumab treatment or other strategies to reduce basophil activation in lupus will prove efficacious remains to be seen. Nonetheless, this work opens new avenues of investigation in lupus and, at the very least, we have gained an understanding of how autoantibody production is enhanced in this disease,” said Juan Rivera, Ph.D., the study’s senior author and deputy scientific director at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the NIH institute that conducted the study. Support for the effort was also provided by the National Institute of Dental and Craniofacial Research.

In addition to testing omalizumab’s potential and safety for treating lupus nephritis, Rivera says the group’s future research will explore other ways that IgEs can be prevented from binding with basophils. They will also attempt to determine whether or not depleting or inactivating the basophil population might reduce the production of self-reactive antibodies that can lead to kidney damage in SLE.

More information about systemic lupus erythematosus can be found at http://www.niams.nih.gov/Health_Info/Lupus/default.asp.

More information about the NIAMS Molecular Immunology Section can be found at http://www.niams.nih.gov/Research/Ongoing_Research/Branch_Lab/Laboratory_Molecular_Immunogenetics/mis.asp.

Women who take a certain class of antidepressants during pregnancy may increase their risk of having a miscarriage by 68 percent, Canadian researchers report.

Antidepressant use is common during pregnancy, with up to 3.7 percent of women taking the drugs during the first trimester. Stopping treatment can lead to a return of depression and other symptoms, and previous studies of the medications’ effects on the fetus have been small and had contradictory results.

But the Canadian case-control study on more than 5,000 women found that by controlling for other factors associated with miscarriage, taking antidepressants known as selective serotonin reuptake inhibitors (SSRIs) during pregnancy led to an increased risk of miscarriage.

Up to 20 percent — or one woman out of five — will suffer a miscarriage for various reasons during pregnancy. But the study results suggest that SSRIs as a class increase that risk, according to lead researcher Anick Berard, an associate professor at the University of Montreal.

The results “are highly robust given the large number of users studied,” she wrote.

In addition, she said, the study makes clear that the drugs, rather than the mothers’ depression and anxiety, are associated with an increased risk for miscarriage.

However, the author of an accompanying editorial noted that the finding is far from definitive.

“This is an association, not a cause,” said Adrienne Einarson, assistant director of the Motherisk Program at the Hospital for Sick Children in Toronto. “We still don’t know if it’s the depression or the drug.”

Also, the risk uncovered by the study is a very small one, Einarson added. “Less than twice as many women had miscarriages in the group with antidepressants as those who did not take antidepressants. It’s a very small risk indeed, and it’s not a reason to stop taking an antidepressant if you need it.”

For the study, Berard’s team collected data on 5,124 women who had clinically verified miscarriages and compared them with another group of women who had not miscarried.

Of the women who had miscarriages, 5.5 percent were taking an antidepressant during their pregnancy, the researchers found.

The most commonly used antidepressants were SSRIs. Among these, paroxetine (Paxil) and venlafaxine (Effexor) were associated with a 51 percent increased risk of miscarriage, Berard said.

The risk of miscarriage also increased with higher daily doses of these drugs. In addition, using a combination of different antidepressants doubled the risk of miscarriage, the researchers noted.

Berard believes that as part of pregnancy planning, women should discuss with their doctor the risks and benefits associated with different types of antidepressants.

“I would certainly advise against using Paxil and Effexor early on in pregnancy,” she said. “This doesn’t mean women can’t use antidepressants; there are others on the market. Planning pregnancy and actually choosing which type of therapy beforehand is an option.”

Einarson noted that many women with depression are undertreated.

“My bottom, bottom, bottom line is that if a woman needs to be on an antidepressant, she must continue to take it. This should not be a reason to stop it,” Einarson said.

Another expert, Dr. Salih Yasin, associate professor and vice chair of obstetrics and gynecology at the University of Miami Miller School of Medicine, said this study can be useful in guiding doctors in advising patients.

First, one should determine whether the woman should be taking an antidepressant or not, Yasin noted. “There are many people who have depression, but don’t need medication,” he said.

“With patients who need medications, one has to pick the lowest dose of the ones that have the least association with miscarriage,” Yasin said.

The report is published in the May 31 edition of the Canadian Medical Association Journal.

SOURCES: Anick Berard, Ph.D., associate professor, epidemiology, University of Montreal, and director, Research Unit on Medications and Pregnancy at CHU Ste-Justine, Montreal; Adrienne Einarson, R.N., assistant director, Motherisk Program at The Hospital for Sick Children, Toronto; Salih Yasin, M.D., associate professor and vice chair, obstetrics and gynecology, University of Miami Miller School of Medicine.

Drug manufacturers develop new drugs under patents that protect their firms’ investments in the products. When patents or other periods of exclusivity on the new drugs expire, manufacturers can seek approval from FDA to sell generic versions.

Generic drugs are identical to their brand-name equivalents in dosage, safety, strength, quality, performance characteristics, intended use, and the way they’re administered to patients.

Generic drugs cost about 30 to 80 percent less than their brand-name counterparts. A recent analysis by IMS Health, which provides market intelligence to the pharmaceutical and health care industries, found that generic medicines saved the U.S. health care system more than $734 billion from 1999 to 2008.

Researchers have shown that ranibizumab (Lucentis) eye injections, often in combination with laser treatment, result in better vision than laser treatment alone for diabetes-associated swelling of the retina.

Laser treatment alone has been the standard care for the past 25 years. But nearly 50 percent of patients who received this new treatment experienced substantial visual improvement after one year, compared with 28 percent who received the standard laser treatment. The study involved 52 clinical sites within the Diabetic Retinopathy Clinical Research Network (DRCR.net), supported by the National Eye Institute (NEI) and the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health.

“These results indicate a treatment breakthrough for saving the vision of people with diabetic macular edema,” said Neil M. Bressler, M.D., chair of the DRCR.net and chief of the Retina Division at the Wilmer Eye Institute, Johns Hopkins University, Md.”Eye injections of ranibizumab with prompt or deferred laser treatment should now be considered for patients with characteristics similar to those in this clinical trial.”

Diabetic retinopathy is the most common cause of vision loss in working-age Americans. This condition damages the small blood vessels in the eye’s light-sensitive retinal tissue. When these damaged blood vessels begin to leak fluid near the center of the retina, known as the macula, macular edema occurs. The macula provides detailed central vision used for activities such as reading, driving, and distinguishing faces. In macular edema the retinal tissue swells, which can lead to vision loss if left untreated.

Laser treatment of the retina has been the standard care for diabetic macular edema since an NEI-supported study in 1985 showed it to be beneficial. However, recent small short-term studies have revealed the visual benefits of eye injections of medications that block a chemical signal that stimulates blood vessel growth, known as vascular endothelial growth factor (VEGF). These studies have indicated that repeated doses of anti-VEGF medications, such as ranibizumab, may prevent blood vessels from leaking fluid and causing macular edema. The DRCR.net study, published online April 27 in Ophthalmology, confirms preliminary results and provides evidence of the treatment’s effectiveness in combination with laser therapy through at least one year of follow up.

“This comparative-effectiveness study demonstrated that a new treatment can protect and, in many cases, improve the vision of people with diabetic macular edema,” said NEI Director Paul A. Sieving, M.D., Ph.D.

The current study included a total of 854 eyes of 691 people, who had one or both eyes treated. Participants, who were on average in their early 60s, were diagnosed with type 1 or 2 diabetes and macular edema. They were randomly assigned to one of four study groups: sham injections plus prompt laser treatment within one week; ranibizumab injections plus prompt laser treatment; ranibizumab plus deferred laser treatment after six months or more; or injections of corticosteroid medication known as triamcinolone (Trivaris) plus prompt laser treatment.

Ranibizumab injections could be given as often as every four weeks, and triamcinolone injections or laser treatments could be given as often as every 16 weeks. In general, treatment was continued until a participant’s vision or retinal thickness returned to normal, or additional treatment did not improve vision or retinal swelling.

After one year, nearly 50 percent of eyes treated with ranibizumab and prompt or deferred laser treatment showed a substantial visual improvement. People could read at least two additional lines on an eye chart with the treated eye, or letters that were at least one-third smaller than they could read before the study treatment. Fewer than 5 percent of eyes in these groups experienced a visual loss of two or more lines. The results were similar whether patients received prompt or deferred laser treatment with the ranibizumab injections.

In contrast, about 30 percent of eyes that received laser treatment alone or triamcinolone plus laser showed a visual improvement of two or more lines on an eye chart, while 13 to 14 percent of eyes in these groups had a visual loss of two or more lines.

Although participants in all three injection groups had a greater decrease in retinal thickness after one year than with laser treatment alone, patients who received triamcinolone injections had greater complication rates. About 30 percent of people in the triamcinolone group developed high eye pressure that required medications, and about 60 percent developed cataracts that required surgery.

Few participants who received eye injections of ranibizumab had eye-related complications, such as an infection inside the eye likely caused by the injections, or worsening of a retinal detachment that existed prior to beginning treatment. The study found that eye injections of ranibizumab were not associated with any serious risks such as heart attack or stroke. DRCR.net researchers will continue to monitor the study participants for at least three years to obtain additional information about the safety and effectiveness of these macular edema treatments.

The U.S. Food and Drug Administration today approved the first medical device that uses radiofrequency energy to treat severe and persistent asthma in certain adults.

The Alair Bronchial Thermoplasty System is intended for patients ages 18 and older whose severe and persistent asthma is not well-controlled with inhaled corticosteroids and long-acting beta agonist medications.

The device is composed of a catheter with an electrode tip that delivers a form of electromagnetic energy, called radiofrequency energy, directly to the airways. A controller unit generates and controls the energy.

Inflammation causes the airways of people who have asthma to swell and narrow, making breathing difficult. The Alair system treats asthma symptoms by using radiofrequency energy to heat the lung tissue in a controlled manner, reducing the thickness of smooth muscle in the airways and improving a patient’s ability to breathe. To benefit, patients will require multiple sessions targeting different areas in the lungs.

“The approval of the Alair system provides adult patients suffering from severe and persistent asthma with an additional treatment option for a disease that is often difficult to manage,” said Jeffrey Shuren, M.D., J.D., director of the FDA’s Center for Devices and Radiological Health.

The FDA based its approval on data from a clinical trial of 297 patients with severe and persistent asthma. The trial showed a reduction of severe asthma attacks with use of the Alair system.

The FDA is requiring a five-year post-approval study of the device to study its long-term safety and effectiveness. The device manufacturer, Asthmatx, will follow many of the patients who were enrolled in the clinical trial and enroll 300 new patients at several medical centers across the United States.

Possible side effects during the course of treatment may include asthma attacks, wheezing, chest tightness or pain, partially collapsed lung (atelectasis), coughing up blood (hemoptysis), anxiety, headaches, and nausea. The Alair system is designed to reduce the number of severe asthma attacks on a long-term basis. However, there is a risk of immediate asthma attacks during the course of the treatment.

The Alair system is not for use in asthma patients with a pacemaker, internal defibrillator, or other implantable electronic device. Also, those patients with known sensitivities to lidocaine, atropine, or benzodiazepines should not use the device. Alair has not been studied for success in retreatment of the same area of the lung. Currently, patients should not be retreated with the Alair system in the same area of the lung.

Asthma patients considering the Alair system should not be treated while the following conditions are present: an active respiratory infection, coagulopathy (bleeding disorder), asthma exacerbations, or if they have had changes to their corticosteroid regimen 14 days before the proposed treatment.

Asthmatx Inc. is based in Sunnyvale, Calif.

Most women who have had a Cesarean delivery can safely have a vaginal delivery later, an expert panel concluded Wednesday.

Surging C-section rates in the United States have worried experts, but the panel said that just because a woman has had a C-section in the past, there’s no reason she must have one in subsequent deliveries.

However, current medical practice and fear of lawsuits are major obstacles to encouraging women to have a vaginal delivery after a C-section, the National Institutes of Health-sponsored panel said.

“This meeting was stimulated by the rising Cesarean rate all over this country, as well as the world,” Dr. F. Gary Cunningham, Panel and Conference Chairman and Beatrice and Miguel Elias Distinguished Chair in Obstetrics and Gynecology at the University of Texas Southwestern Medical Center at Dallas, said during an press conference Tuesday afternoon.

Women who have one C-section are likely to have more C-sections down the line, Cunningham said.

“This has created some problems,” he said.” Another problem has been the voices of many women who have bemoaned the fact that they have not had access to care where a trial of labor can be offered as an delivery.”

In the United States, the rate of vaginal delivery after a prior Cesarean has dropped from 30 percent to about 10 percent over the past 15 years, Cunningham noted.

To come up with their recommendations, the panel looked at all the available data as well as hearing testimony from doctors, hospital administrators and academics.

Cunningham was careful to note that the panel’s findings are not guidelines to be followed, but rather a call to consider alternatives to current practice.

“What we found was the use of a vaginal delivery after Cesarean is certainly a safe alternative for the majority of women who have one prior Cesarean,” he said.

There are several major reasons why this choice has been precluded in most hospitals, Cunningham said. “The number of hospitals offering ‘trial of labor’ is diminished because of the perceived good and bad outcomes that accrue to either the mother or the fetus,” he noted.

Although these outcomes are relatively rare, they include a ruptured uterus, and they can be devastating to the mother, Cunningham noted.

In many cases, access to vaginal delivery is not available to these women because of lack of money, as well as doctors’ and hospitals’ fear of being sued should a complication occur, he added.

In addition, some professional societies, such as the American College of Obstetricians and Gynecologists (ACOG) have guidelines that in some cases are impossible to follow, which have caused many hospitals to shy away from offering vaginal delivery to women who have had a Cesarean delivery, Cunningham said.

For example, the ACOG guidelines require that a surgeon and an anesthesiologist be immediately available when a woman who has had a previous C-section gives birth vaginally.

However, there’s no evidence that this type of oversight is necessary or changes outcomes, Cunningham said. In any case, bad outcomes remain rare — Cunningham estimated that there are about 10 deleterious outcomes for every 100,000 births, vaginal or otherwise.

“That doesn’t mean it doesn’t apply, just that there is no evidence to support that,” he said. “It is a crippling rule for many hospitals and physicians, and is therefore a big driver of the problem. We hope that some of the recommendations cause some of these barriers to be removed.”

Yet, there are no reliable means to spot which women are at risk for complications if they opt for vaginal delivery, the panel members noted.

“Pregnancy is something of a risky endeavor,” panel member Carol J. Rowland Hogue, the Jules & Uldeen Terry Professor of Maternal and Child Health and director of Women’s and Children’s Center at the Rollins School of Public Health at Emory University in Atlanta, said during the teleconference.

“Women do suffer complications of pregnancy and their babies do have problems. Fortunately these are rare, but they are irrespective of mode of delivery,” she said.

Panel member Dr. Nancy Frances Petit, chairwoman of the division of obstetrics at St. Francis Hospital in Newark, Del., said there is a need for women and their doctors to communicate better to decide which type of delivery is best.

“It is important for the health-care provider to share with the women, first of all, what are the capabilities of the institution that would be participating in her delivery. What is the level of comfort the health-care provider has in terms of her identified risk. It is also important that in return that he or she really takes the opportunity to listen to what the pregnant woman has to say in terms of what her desires truly are,” Petit said.

Two separate scientific teams announced this week that they had successfully sequenced individual genomes to pinpoint precise genetic causes of illness — breakthroughs that open the door to a future of individualized, genomics-based medicine.

“This is another milestone in the inevitable march towards personalized genetic health,” said Dr. Robert Marion, chief of genetics and development medicine and director of the Center for Congenital Disorders at Children’s Hospital at Montefiore Medical Center in New York City. “Medicine is going to change from waiting for symptoms to develop to knowing what this person is at risk for and being able to stop that from happening. Eventually, we’re talking about prevention.”

One day in the future, Marion predicted, doctors will be able to look at all 20,000 or 25,000 genes in a newborn baby and be able to say whether the child has specific genetic disorders, or a twofold increased risk of developing colon cancer or a higher chance of developing childhood asthma.

And the cost to perform such feats has come way down, with experts at one company predicting that genomes could one day be sequenced for as low as $5,000. Right now, the cost hovers closer to $50,000.

“When it gets to the point where it would cost less to sequence the genome using these techniques than it does to send off a sample to test for a few genes, then you can start moving medicine from just seeing people who are sick to trying to prevent people from getting sick,” said Dr. Jeffery Vance, director of the Center for Genomic Medicine at the Hussman Institute for Human Genomics, University of Miami Miller School of Medicine. “You can see where things are going. This is showing that it’s practical, it can be done and that medicine will start slowly to move toward using this technique as a diagnostic technique for all these individuals and families who have what looks like an inherited disease but not a big family history.”

And, Vance pointed out, genes don’t change like cholesterol and blood pressure do. These tests would only have to be performed once.

The predictions are based on breakthroughs reported this week in two journals, the New England Journal of Medicine and Science.

Dr. James Lupski, vice chair of molecular and human genetics at Baylor College of Medicine in Houston, was both the lead author and the subject of the NEJM study. Lupski suffers from a genetic disorder, Charcot-Marie-Tooth syndrome, which affects nerve function.

By sequencing his genome, the NEJM authors were able to trace the disorder to mutations in copies of the SH3TC2 gene he and three siblings inherited from healthy parents.

For Lupski, who already knew he had this disease, the findings probably don’t come as much of a shock. But suppose people don’t know they have this or another single-gene conditon?

In the old days — meaning last week — experts would have had to suspect which disease the patient had, then hone in on the area of the genome thought to be associated with the disorder. Even then, the results could be far from certain.

“The breakthrough is that now we would be able to make this diagnosis without having any preconceived idea that the patient had Charcot-Marie-Tooth disease,” Marion said.

The second team of researchers sequenced the genomes of two parents and two children from the same family with single-gene diseases. They reported that only 60 of the three billion base pairs in the human genome mutate randomly each generation. That’s about half the rate of mutation that was thought to be passed generation to generation.

How were scientists able to make these leaps?

One big factor has been the advent of new technology with the ability to sequence large amounts of DNA very quickly, explained Marion. Previous technology could only analyze bits of material at a time.

For now, the technology is likely to be helpful only with single-gene disorders which, when it comes to genetics, are relatively easy targets.

“It becomes more difficult with complex disorders because these disorders are not due to one single gene but a combination of genetic factors in multiple genes, as well as environmental factors,” said Marion, author of Genetic Rounds: A Doctor’s Encounters in the Field that Revolutionized Medicine.

“For single-gene disorders, this technology is a breakthrough,” he continued. “But for the more complicated polygenomic or multifactorial conditions, which is every condition that affects humans — diabetes, blood pressure, coronary artery disease and cancer — there’s a complex interplay between multiple genes and the environment. And sorting that out using the technology we have available now is still not possible.”

“Right now, it has its biggest effect where one of the 25,000 or so genes we have by itself doesn’t work right,” Vance agreed. “It won’t have much effect on common diseases like cancer and Alzheimer’s.”

Another expert agreed that the breakthrough could have its limits.

“This showed that there’s tremendous variability between individuals, and if you’re a cup-is-half-full kind of guy, this creates wonderful possibilities for the concept of personalized medicine,” said Richard H. Finnell, professor of environmental and genetic medicine at Texas A&M Health Science Center Institute of Biosciences and Technology in Houston.

“But if you’re a cup-is-half-empty kind of guy, we’ve been treating a lot of disorders with aspirin for a heck of a long time without differentiating individuals or even necessarily knowing what the mechanism of action of a drug is and [still] gotten some benefit,” he noted.

But, for many patients, an accurate diagnosis will at least be a move in the right direction.

“If you were the parent of a child with a disorder and you had taken your child to doctor after doctor after doctor and were given either no diagnosis or a vague diagnosis, to even have a clear-cut diagnosis that doesn’t come with an intervention, that’s a huge step forward and a great relief,” Finnell said.

In the meantime, traditional genome-wide association studies, which compared the genomes of people who had a disease with people who didn’t have the disease, are going to be “left in the dust,” Marion said.

SOURCES: Robert Marion, M.D., chief of genetics and development medicine and director, Center for Congenital Disorders, Children’s Hospital at Montefiore Medical Center, New York City, and author, Genetic Rounds: A Doctor’s Encounters in the Field That Revolutionized Medicine; Jeffery Vance, M.D., Ph.D., director, Center for Genomic Medicine, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine; Richard H. Finnell, Ph.D., professor of environmental and genetic medicine, Texas A&M Health Science Center Institute of Biosciences and Technology, Houston; 2010, Science; New England Journal of Medicine

Among children and teenagers with asthma, those who also have peanut allergies may have more or more-severe asthma attacks, a new study suggests.

Researchers found that among 160 5- to 18-year-olds with asthma seen at their center, the 46 with peanut allergies generally had more hospitalizations for asthma exacerbations than children without the food allergy. They also had a higher rate of treatment with oral corticosteroids — anti-inflammatory drugs given for a short period to control severe asthma symptoms.

Of children and teens with peanut allergy, 23 percent had ever been hospitalized for asthma after the age of 3. That compared with 16 percent of those without peanut allergy.

When it came oral steroids, only 28 percent of kids with peanut allergy had never needed treatment after age 3. That figure was 37 percent among those without the food allergy, according to lead researcher Dr. Alyson Simpson, of Alfred I. duPont Hospital for Children in Wilmington, Delaware.

When she and her colleagues accounted for other factors — like family history of asthma and any other allergies the children had — peanut allergy remained linked to higher risks of hospitalizations and oral steroid use.

The goal in children’s asthma care is to avoid hospitalizations and oral steroids whenever possible, Simpson noted in an interview with Reuters Health, so any increase in those rates is concerning.

She said that parents of children with both asthma and peanut allergy should be particularly sure to work with their child’s doctor to keep the asthma well-controlled. That typically means minimizing kids’ exposure to their particular asthma triggers, helping them maintain a healthy weight and, often, giving them medications that prevent asthma attacks.

Simpson and her colleagues report the findings in the Journal of Pediatrics.

Asthma symptoms arise when the airways become inflamed; that inflammation is most commonly triggered by exposure to allergens, such as pollen, mold or animal dander. Food allergies can also spur asthma symptoms.

It is not clear, however, why study patients with peanut allergy tended to have more problems with asthma control, according to Simpson. Her team’s findings point to an association between peanut allergy and more asthma exacerbations, but do not prove that the food allergy is the cause.

“The exact link is still being studied,” Simpson said.

Understanding the connection is important, she and her colleagues note, as recent studies suggest that both peanut allergy and asthma are on the rise among children — for reasons that are unclear.

It’s estimated that just over 1 percent of U.S. children have peanut allergy, while roughly 9 percent have asthma, according to the American Academy of Asthma, Allergy & Immunology.

SOURCE: Journal of Pediatrics, online.