Washington -- More than half of the American population is dieting each year, Susan Roberts, PhD, director of the Tufts University Energy Metabolism Laboratory in Boston, told congressional staffers at a recent briefing. And nearly all dieters regain their lost pounds in short order.

In fighting the obesity epidemic that has swept the nation and brought with it soaring levels of diabetes, physicians are being called upon to help patients lose weight. But which diet, if any, can be recommended? Roberts had some advice.

She related her tips at a March 11 briefing sponsored by the Congressional Biomedical Research Caucus. This group provides a forum for members of Congress and their staffs to interact with researchers. The briefing was hosted by the Coalition for the Life Sciences, a Maryland-based alliance of six nonprofit professional organizations that focus on basic biological research.

Not only are extra pounds taking a toll on health, but the diets they inspire are painful to the pocketbook as well, Roberts noted. Consumers are spending an estimated $35 billion a year on weight-loss products and services.

As a first step in determining a solution, Roberts explored how the extra pounds came to settle on the nation's bellies and waists. Since the mid-1970s, the number of calories the average person has consumed each day has increased by about the equivalent of an extra meal, she said. And the two food ingredients that account for most of the added calories are high fructose corn syrup and oil. Flour, cheese, shortening and edible beef tallow each contribute a bit more.

Americans spend around $35 billion a year on weight-loss products and services.

What has not increased is the consumption of beef, seafood, candy, chocolate and chips. Consumption of ice cream and frozen desserts actually fell by 13%.

Boosting the amount of energy burned by the body is a good way to shed extra pounds, but to maintain weight loss, food intake must drop permanently, she said. And no weight-loss program can work overnight, despite advertised claims, Roberts stressed. "Losing significant amounts of fat is a long-term project."

Individuals need to have realistic expectations, she noted. Weight loss of about 1 to 2 pounds per week is the maximum that can be expected.

"There is no magic bullet for belly fat. Energy intake needs to be reduced for a long time to lose weight, and then permanently decreased to keep weight off."

Roberts recommends consuming foods that help satisfy "basic hard-wired biology." For example, hunger is one pressing need that should be satisfied with high-fiber, high-protein foods rather than cookies and chips. The desire for variety can be met with salads, soups and fruit.

Often, "we eat it because it's there," she said, citing a study in which people opted to eat the larger bucket of stale popcorn rather than a smaller amount of freshly popped kernels.

In 2008, the average American consumed the caloric equivalent of one meal a day more than was eaten in the mid-1970s.

Society also needs to get involved. Consumers must take charge of their food environment to make it easier to lose weight, and parents should play a role in the types of food served to their children at school, she advised.

The American Medical Association also has made the effort to combat obesity a priority and has called for societywide involvement that includes schools, public health and medical education.

Additionally, Roberts would like the media to reject advertising for untested diet gimmicks and scientists to continue to research what works best from the biological perspective.

She also recommended a federal junk-food tax. But at least one congressional staffer indicated that was not likely to happen anytime soon.

This content was published online only.

Centers for Disease Control and Prevention surveillance data for the week ending March 14 indicate that U.S. flu activity slightly decreased, with 30 states reporting widespread activity -- five fewer than in the previous report, and 18 more with regional activity.

Every year the CDC monitors the influenza virus, focusing on type A strains, H1N1 and H3N2, and type B strains. Since the beginning of the 2008-09 flu season, type A (H1N1) viruses have been dominant. But in recent reporting periods, several regions noted a higher relative proportion of influenza B viruses than at the national level or in other regions.

During the current season, the CDC also detected a significant increase in resistance to flu antivirals in one of the circulating strains.

The flu types and subtypes on this watch list are the viruses that circulate every year, though the proportion of strains is different, explained Nila Dharan, MD, an epidemic intelligence service officer in the CDC's Influenza Division. In addition, the prevalence and proportion can vary during the course of a flu season among communities and even within a specific community, according to CDC materials. These changes in type and subtype affect which antiviral drug will be most useful.

For physicians, this reality can be problematic when it comes to selecting flu antivirals. In an office setting, doctors can be limited as to what information tests will provide about a patient's influenza, Dr. Dharan said. A quick test can confirm the presence of the flu virus and sometimes will be sensitive enough to tell if it is a type A or B. "But that's it," she added.

The U.S. Strategic National Stockpile has 50 million courses of neuraminidase inhibitors to treat flu.

Dr. Dharan also noted, though, that a physician can make a more effective choice by being aware of what strains are circulating in his or her region or even more locally. But still, influenza treatment and chemoprophylaxis with antivirals is no easy proposition.

Two drug classes exist. The newer drugs are the neuraminidase inhibitors -- oseltamivir or Tamiflu and zanamivir or Relenza. The second category, the adamantanes, is made up of amantadine and rimantidine, which is marketed as Flumadine.

To date, 100% of H3N2 viruses have tested resistant to adamantanes. Though all flu strains remain susceptible to zanamivir, this drug has limitations that make it unsuitable for certain categories of patients at very high risk for flu complications. Meanwhile, the adamantanes are not active against type B strains. Emerging resistance to oseltamivir has added to this complexity.

"Before last year, there was very little resistance to oseltamivir among routinely tested viruses -- less than 1%," Dr. Dharan said. But during the 2007-08 flu season, this circumstance changed as resistance to this antiviral reached 12%. During that period, though, H1N1 viruses made up only about 19% of circulating strains. Therefore, the proportion of overall resistance among all influenza viruses tested was not high.

The figures for the 2008-09 season thus far reveal a different picture. Seventy-five percent of circulating strains have been type A and 24% have been type B. Unfortunately, the vast majority of type A viruses are H1N1, and about 98% of H1N1 viruses tested are resistant to oseltamivir.

Experts highlight specific messages from this situation.

100% of H3N2 viruses have tested resistant to adamantanes.

The current resistance situation makes the flu vaccine more important than ever, especially because the vaccine for the 2008-09 season and for that of 2009-10 protects against the strain of H1N1 that is resistant to oseltamivir.

Also, resistance to these antivirals functions differently than that of the usual understanding of antibacterial resistance. Because flu virus is constantly mutating and changing, it is "not necessarily the case that the resistance will persist next year," Dr. Dharan said.

In response to the growing resistance, though, the CDC updated the public health recommendations regarding the selection of antiviral drugs in December 2008. This document directs physicians to use a combination of oseltamivir and rimantadine. Zanamivir also remains an option when appropriate.

Antivirals and the national stockpile

Meanwhile, the current resistance profile warrants attention for reasons far from the day-in, day-out concerns of the exam room. These reasons are related to pandemic preparedness.

"We are watching this very carefully," said Robin Robinson, PhD, director of the Biomedical Advanced Research and Development Authority, which is part of the Dept. of Health and Human Services Office of the Asst. Secretary for Preparedness and Response.

Influenza antivirals have been considered by public health experts to be an important medical countermeasure in the event of a pandemic influenza epidemic. The U.S. Strategic National Stockpile, for instance, houses 50 million treatment courses of the neuraminidase inhibitors. Of this amount, the ratio is 80 to 20, oseltamivir to zanamivir. The stockpile also holds 2.8 million courses of rimantidine.

Officials have been monitoring the resistance situation for at least 18 months, Robinson said, and active deliberation continues. Compared with other countries, the U.S. oseltamivir-zanimivir ratio falls in the middle -- some nations have more oseltimivir, some less. "But no country has made a drastic change yet," he said. A decision about whether to take steps to adjust the stockpile's makeup could occur later this spring.

Robinson also noted that historical data show influenza viruses, even within the H1N1 subtype, can "burn out." In this case, the emergence of the resistant strains has not been driven by exposure to the drugs or, therefore, selective pressure. Instead, it is a natural mutation.

This content was published online only.

A desire to continue providing colonoscopy, combined with a lack of resources, led one physician to offer the procedure without sedation. Now, that solution may lead to no-sedation colonoscopy becoming a more widely considered option.

A few years ago, the Sepulveda Ambulatory Care Center in North Hills, Calif., experienced a nursing shortage, and Felix Leung, MD, a staff gastroenterologist, was faced with two options. He could stop performing the procedure, or he could start offering it without sedatives. The Sepulveda center is part of the Veterans Affairs Greater Los Angeles Healthcare System. In response to patients who didn't want to travel 15 miles to another facility, he offered the no-sedation approach. Quite a few -- 30% between 2002 and 2005 -- accepted.

"The veterans asked if there was an alternative, and we found out that unsedated colonoscopy is done in many parts of the world," said Dr. Leung, who also is a professor of medicine at the David Geffen School of Medicine at the University of California, Los Angeles. "The U.S. seems to be unusual in that we, by and large, only do sedated colonoscopy."

He has since documented his experiences in a series of papers, including one in the December 2008 Journal of Family Practice. This article reported that, from September 2002 to June 2005, 145 out of 483 eligible patients opted to undergo colonoscopy without sedation. Of this group, 112 were able to complete it. Twenty-six could not, because of the discomfort, and later underwent sedated colonoscopy or barium enema. Another seven had poor bowel preparation or obstructing lesions that blocked the procedure. Some physicians said these numbers indicated that unsedated colonoscopy is a viable alternative.

"It's not going to be for everyone, but it's an option that I think patients would want to consider," said Thomas Kintanar, MD, a family physician in Fort Wayne, Ind. "There are some patients who will do just great without any anesthetic." He is also a board member of the American Assn. for Primary Care Endoscopy, although he was speaking for himself.

Colonoscopies without sedation are common in Europe and Asia.

Colonoscopy without sedation is common in Europe and Asia, and efficacy is comparable.

"There have been several studies that show that if you have motivated patients, a significant fraction of them can have a colonoscopy without sedation," said Douglas Rex, MD, past president of the American College of Gastroenterology. "But what has to be kept in mind is that most American patients actually prefer to be sedated. If you use sedation, there is better patient satisfaction and better physician satisfaction. That's really important."

Dr. Rex, who is also professor of medicine at Indiana University School of Medicine and director of endoscopy at Indiana University Hospital, has performed a small number of colonoscopies on unsedated patients and has undergone one without sedation himself. "For the great majority, having sedation offers a lot of advantages and a lot of positives," he said.

But with the demand for colonoscopy growing, performing it without sedation could reduce both associated work force needs and costs to the health care system. In his efforts, for instance, Dr. Leung eliminated the need for two registered nurses.

Also, a report released Jan. 7 by the Lewin Group, a health care consulting firm, projected that demand for gastroenterologists would grow at a rate nearly double the supply. If this projection bears out, it could impact the availability of traditional colorectal cancer screening, thereby increasing interest in the no-sedation option.

Neither the American Gastrological Assn. nor the ACG has policy regarding no-sedation colonoscopy. In broader terms, ACG policy notes that a well-trained endoscopist is key to a good colonoscopy. The American Academy of Family Physicians takes the position that family physicians trained in colonoscopy should be allowed to perform them and that specialty should not affect privileging.

Going without sedation also could provide some benefits for patients. Dr. Leung discovered many preferred being able to communicate and remember the conversations with the physician during and after. In addition, the unsedated approach is less expensive and does not require patients to have an escort or restrict activities afterward.

"Some patients just didn't have anybody to shuttle them around, and these patients would not have been able to have screening by colonoscopy if this option was not available," Dr. Leung said.

Additionally, this approach cuts to zero the already very low risk of complications associated with the sedative medications and significantly reduces the chance of a perforation.

"You cannot perforate [the bowel of] an awake patient. They will get off the table and smack you," said Ricardo G. Hahn, MD, professor of family medicine at the University of Southern California in Los Angeles. Unsedated colonoscopy is "not a comfortable procedure, but it's only once every five to 10 years."

Dr. Hahn co-authored a paper in the September-October 2007 Journal of the American Board of Family Medicine comparing unsedated colonoscopy with flexible sigmoidoscopy in a family medicine clinic.

Several physicians, however, expressed caution, because unsedated colonoscopy may not be possible or appropriate for everyone. Data from a VA population, which tends to be older and predominantly male, may not apply to the wider world. For example, female physiology tends to make this procedure more difficult.

Experts also worry that an uncomfortable experience may keep a patient from completing this screening.

"The key for us is to ensure a good exam, a comfortable exam for the patient and one that they are willing to repeat," said David A. Johnson, MD, professor of medicine and chief of gastroenterology at Eastern Virginia School of Medicine. He also is an ACG past president.

Dr. Leung's upcoming projects will look at colonoscopy techniques, such as using water infusion without air insufflation, to reduce the discomfort related to the procedure and allow more patients to have it done without or with less sedation.

The print version of this content appeared in the Jan. 19, 2009 issue of American Medical News.

Washington -- The Food and Drug Administration is asking the manufacturers of new drugs and biologics for type 2 diabetes to be more diligent in determining if their therapies pose cardiovascular risks.

Until now, manufacturers had only to show that their drugs reduced blood sugar levels.

"We need to better understand the safety of new antidiabetic drugs," said Mary Parks, MD, director of the agency's Division of Metabolism and Endocrinology Products at the Center for Drug Evaluation and Research. She released a guidance document outlining the agency's recommendations for doing such an assessment Dec. 17, 2008.

More than 23 million people in the U.S. have been diagnosed with type 2 diabetes, which places them at a two- to four-times greater risk of heart disease than their nondiabetic counterparts. None of the currently approved antidiabetic therapies has been proven convincingly to reduce that risk, the FDA said.

The guidance, which is effective immediately, asks that phase II and III clinical trials demonstrate that new therapies do not increase cardiovascular risk in comparison with existing therapies.

More than 23 million people in the U.S. have type 2 diabetes.

The FDA also recommends to manufacturers that any cardiovascular events occurring in their trials be analyzed by committees of outside cardiologists.

The FDA already has placed black-box warnings on one class of type 2 diabetes drugs, thiazolidinediones, or TZDs, after they were found in postmarketing studies to increase the risk of heart failure. Two drugs, Avandia, or rosiglitazone, and Actos, or pioglitazone, are in that class.

Alarms about Avandia's association with increased heart risks were raised in a May 2007 New England Journal of Medicine article by Steven Nissen, MD, chair of Cleveland Clinic's Dept. of Cardiovascular Medicine. At the time, Dr. Nissen noted that because of this risk, Avandia is not a drug he recommends to patients.

GlaxoSmithKline, the manufacturer of Avandia, strongly disagreed with the conclusions in the NEJM article, faulting the authors' reliance on a meta-analysis rather than on long-term trials that Glaxo said showed no increased cardiovascular risk associated with Avandia.

Meanwhile, in a study published online Dec. 10, 2008, by the Canadian Medical Assn. Journal, researchers found that the risk of fractures doubled among older women who take TZDs for one year or more to control their diabetes.

"We knew going into this study there was an association between thiazolidinediones and fracture risk. However, the magnitude of the risk had not been evaluated," said Sonal Singh, MD, MPH, an assistant professor of internal medicine at Wake Forest University School of Medicine in Winston-Salem, N.C., and a co-researcher for the study.

Glaxo responded that the bone fracture risk had been reported previously and is noted on the Avandia label. A study to evaluate the effects of the drug on bone in women with type 2 diabetes is now enrolling participants, a spokesman said.

But in a commentary published online Dec. 10, 2008, in the CMA journal, Lorraine L. Lipscombe, MD, an adjunct researcher at the Institute for Clinical Evaluative Sciences in Toronto, recommended that TZDs not be considered a first-line therapy for type 2 diabetes.

"If a patient is unable to take other therapies or if other therapies have failed, there may be a role for thiazolidinediones in carefully selected patients duly informed of the potential adverse effects," she wrote.

The print version of this content appeared in the Jan. 19, 2009 issue of American Medical News.

Inhalers such as Serevent Diskus and Foradil Aerolizer, which contain only a long-acting beta agonist, are not good choices for treating asthma. The reason: The chance they will be used without an inhaled corticosteroid is too great, according to three Food and Drug Administration advisory committees that gathered in December 2008. The benefits of inhalers that deliver both types of medicines -- Advair Diskus and Symbicort -- are worth the risks.

"The single agent, long-acting beta agonists should no longer be approved for use in the treatment of asthma. The combination dispensers should continue to be approved for all age groups," said Marsha Rappley, MD, chair of the FDA's Pediatric Advisory Committee and dean of the College of Human Medicine at Michigan State University. Members of the Pulmonary-Allergy Drugs as well as the Drug Safety and Risk Management advisory committees were also in attendance.

The agency is not required to follow its advisory panels' recommendations but generally does.

This is the latest in the checkered history of long-acting beta agonists. Several studies showed that these medications increase the risk of severe exacerbations. Because they seem to reduce symptoms without addressing inflammation, treatment guidelines urge that they be used only with inhaled corticosteroids, which appear to mediate their negative effects. The beta agonists also are not recommended for patients able to control their illnesses on other medications. Prior FDA advisory committee deliberations have led to the drugs remaining on the market, but with stronger warnings about possible adverse events.

Most asthma specialists received news of the latest action with trepidation. On one hand, the combination products are far more commonly prescribed than the inhalers with only a long-acting beta agonist. Also, even if the single products lose an indication for asthma, they are still expected to be labeled for chronic obstructive pulmonary disease -- so they could still be used off-label for asthma patients.

On the other hand, physicians worried about losing the single-drug products as an option or the possibility that all products containing a long-acting beta agonist drug would be pulled from the market. Many physicians view these drugs as very valuable.

"I think their conclusions were conservative and consistent with trying to optimize the safety and the use of these medications. I can see their rationale. But I'm a bit concerned that they're overcautious about the safety signal," said Stanley Szefler, MD, head of pediatric clinical pharmacology at National Jewish Health in Denver. He was speaking personally, although he testified at the joint advisory committee meeting on behalf of the American Academy of Allergy, Asthma and Immunology and the American College of Allergy, Asthma & Immunology.

Concern also stemmed from the idea that this move might limit patient access and affect the cost of treating asthma. These drugs in two inhalers are less expensive than are the combined products.

"From a clinical standpoint, it's nice to have more options. And, from a patient standpoint, I'm concerned about cost. These medications are fairly expensive," said Richard Gower, MD, president of ACAAI. "We live in an imperfect world. All drugs have potential benefits and side effects."

Manufacturers cheered the conclusion that the benefits of combination products outweighed the risks but disagreed with the conclusion that those with only a long-acting beta agonist should no longer be used for asthma.

Statements issued by these companies said these products provided more dosing flexibility and were safe when used as directed.

"We welcome the committee's endorsement of Advair as a safe and effective treatment for asthma. ... Serevent, when used with an [inhaled corticosteroid], is an important treatment option for some patients as outlined in national guidelines," said Ellen Strahlman, MD, chief medical officer for GlaxoSmithKline.

The advisory panels also called for more studies to determine the safety of the combination products in children.

The print version of this content appeared in the Jan. 19, 2009 issue of American Medical News.