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Podcast Transcript - September 18, 2007

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Hello, and welcome to this week’s Annals of Internal Medicine audio summary for our September 18, 2007 issue. I’m Michael Berkwits, Deputy Editor at Annals.

We have another fabulous issue for you this week with a focus on type 2 diabetes. We have important articles on the effects of weightlifting and aerobic training on glycemic control; a systematic review of the comparative effectiveness of oral agents for diabetes treatment; and I’ll be talking to the lead author of this week’s American College of Physicians’ guidance statement on optimal HbA1c target levels. We also have articles on the association between triglycerides and coronary artery disease, and a systematic review of colony-stimulating factors on mortality and infectious disease outcomes. But first, an in-depth summary of this week’s articles.

Our lead article this week is a randomized trial that compares the effects of different types of exercise on glycemic control in patients with type 2 diabetes.

We all counsel our patients with type 2 diabetes to exercise, but we’re usually thinking about aerobic exercise, such as walking, climbing stairs, or riding an exercise bicycle. The role of weightlifting or resistance training in diabetes control is less well recognized, perhaps because so many patients with type 2 diabetes are older and seem past the point where they can pump some serious iron. However observational studies have suggested resistance training is as effective as aerobic exercise at reducing Hb A1c levels.

In this week’s article, lead author Ronald Sigal and his colleagues from the University of Calgary in Alberta Canada directly compared the two forms of exercise in patients with type 2 diabetes. After a 4 week run-in phase to assess adherence to exercise, the researchers gave trial participants a free 6 month membership to the YMCA and randomized them to an aerobic training program 3x weekly, an exercise training program 3x weekly, the combination of both, or usual activity for 26 weeks. They encouraged participants to keep their other physical activity, their diets, and their medications the same, and measured the patients’ HbA1c and lipid levels, blood pressure, and body composition at 3 and 6 months.

The article reports 3 main findings.

First, HbA1c levels declined in all active intervention groups, but the decline was greatest in the combined exercise group, who experienced about a 1% absolute reduction in HbA1c.

Second, there were no significant differences in lipid levels or blood pressure between groups, but patients randomized to aerobic exercise lost more weight, and those in the combination group saw their waists shrink more, than control patients.

And third, aerobic training precipitated angina in 1 patient, spinal stenosis in another, and symptoms of osteoarthritis in 2 other patients.

Based on these findings, the authors conclude that patients with type 2 diabetes obtain the greatest glycemic control doing combined aerobic and resistance exercise, but they acknowledge that patients in the combined exercise group trained longer each week than those doing either regimen alone, so that the effects they observed may be attributable to more exercise overall rather than a difference in effect between types. In an accompanying editorial, William Kraus of Duke University and Benjamin Levine of Presbyterian Hospital of Dallas and UT-Southwestern also point out that the study gives the schedule and frequency of prescribed exercise but it doesn’t say much about how much and how intensely participants actually exercised. However, they ask readers to “imagine an inexpensive pill that could decrease HbA1c by 1%, reduce cardiovascular death by 25%, and improve patients’ functional capacity. Diabetes experts would be quick to incorporate it into practice guidelines and performance measures for diabetes.” Exercise is just such a pill, they imply, which should be prescribed to everyone. But they don’t acknowledge that if it were as easy as just telling patients to get more exercise, there wouldn’t be a diabetes epidemic. Telling patients to exercise is often ineffective. Instead, patients need prescription of specific exercises, durations, and goals as part of a precisely prescribed program if the prescription is to have an effect. Provider interested in improving their prescriptions for lifestyle changes can start by looking at the exercise program detailed in the Appendix of this article.

Our CME article this week is a systematic review of the comparative effectiveness and safety of oral medications for type 2 diabetes. Lead author Shari Bolen and her colleagues from the Johns Hopkins Evidence-Based Practice Center at Johns Hopkins University in Baltimore, Maryland, did a systematic search for controlled trials and other systematic reviews evaluating the benefits and harms of oral agents.

They found 216 trials and 2 reviews that met their criteria, and developed 4 categories of conclusion based on their review of the evidence.

First, there were too few events in too few trials to provide definitive evidence about the comparative effectiveness of the agents on clinical outcomes such as all-cause or cardiovascular mortality, peripheral arterial disease, retinopathy, or nephropathy.

Second, there was strong evidence to suggest that most oral agents were similar in their effects on glycemic control, creating absolute reductions in HbA1c levels of about 1%. Combination therapies reduced HbA1c by an additional 1% compared to monotherapy.

Third, there was strong evidence to suggest that thiazolidinediones, second-generation sulfonylureas, and combinations of metformin and sulfonylureas caused weight gain of 1 to 5 kg compared to metformin alone.

And fourth, there was moderately strong evidence that thiazolidinediones increase both HDL and LDL, and metformin lowered LDL by about 10 mg/dL.

Interested listeners should consult the paper’s Table 1 for a complete listing of the review findings.

The authors acknowledge the limitations of the evidence, including trial durations of < 1 year, few head-to-head comparisons of agents, and incomplete and at times inconsistent reporting of adverse effects. And the review only briefly mentions the current controversy over the cardiovascular safety of rosiglitazone, and it does not summarize evidence about the new drugs class of DP4 inhibitors. Nevertheless, the authors conclude that older agents, such as second generation sulfonylureas and metformin, have similar or superior effects to those of newer, more expensive agents in their effects on glucose, lipids, and other intermediate endpoints, such as weight and blood pressure, and on balance, metformin seemed to have the best risk:benefit profile.

In an editorial, Leonard Pogach of the Veterans Affairs New Jersey Health Care System in East Orange, NJ, notes that this is the first review to summarize all available trials that measured the full range of intermediate endpoints of diabetes, including unpublished trials filed with the FDA and conducted by industry. He emphasizes that treatment decisions must be shared between patient and provider, but that this review provides the foundation for the shared decisions. “Read it now,” he writes, and “keep its main conclusions within arm’s reach as you care for diabetes.”

Subscribers to Annals can receive CME credits by answering 2 quiz questions about this article at cme.annals.org. Just click the “My CME” link, to register or sign in.

This week we’re also publishing a guidance statement from the American College of Physicians about optimal HbA1c targets. Lead author Amir Qaseem and his coauthors from the ACP’s Clinical Efficacy Assessment Subcommittee reviewed guidelines issued by 9 different professional organizations to assess the recommendations for optimal HbA1c targets, and the strength of the evidence underlying those recommendations. They found that the guidelines differed in whether they recommended a target HbA1c level, and most that did used a target level of about 7% but recommended setting individualized target levels based on other factors such as risk for micro- and macrovascular disease, patients life expectancy, and comorbid conditions. Based on their guideline review, the came to three conclusions: first, that target levels should be as low as possible without causing adverse events or an unacceptable patient burden; second, that target levels should be based on individualized assessment of risk of complications, comorbidity, life expectancy, and patient preferences; and third, that more research is needed to determine optimal HbA1c levels, especially in the presence of hypertension and dyslipidemia.

Given the unique nature of this systematic review of guidelines, and given that clinicians are increasingly being asked to meet quality measures for HBA1c control that differ by which guideline is endorsed by which payer or sponsor, I invited the lead author of this week’s article to describe what the Subcommittee is, and what the group learned from its process of reviewing the guidelines. Dr. Amir Qaseem is a Senior Medical Associate at the Department of Clinical Programs and Quality of at the American College of Physicians in Philadelphia.

Q: Dr. Qaseem, thank you for talking to me.

A: Thank you.

Q: What is the Clinical Efficacy Assessment Subcommittee of the ACP?

A: The Clinical Efficacy Assessment Subcommittee is the guideline committee of the ACP and is responsible for the development of guidelines.

Q: This week’s article is a guidance statement. What’s the difference between a guidance statement and a guideline?

A: In our guidelines we perform an evidence review ourselves and our recommendations are based on the evidence. In our guidance statement, rather than developing our own guidelines in the presence of several guidelines on each topic, we review other organizations’ guidelines.

Q: You identified 9 different guidelines for addressing HbA1c targets. What criteria did you use to evaluate the different ones?

A: We used the AGREE instrument. That consists of 23 questions across 6 domains that addresses the scope and purpose of a guideline, clearly describing if the target audience is identified; if there’s a clear recommendation and the goal has been clearly identified for a guideline; and most importantly it addresses the rigor of development of a guideline: if there were systematic search approaches that were used to come up with the evidence and if the benefits, harms, and risks of recommendations were clearly described. Aside from that, the AGREE instrument also addresses applicability of the guideline, clarity and presentation, as well as editorial independence, which is very important to see if the funding body had any influence in terms of development of the guideline recommendations.

Q: This week’s article ends with the recommendation that the ideal HbA1c target level is lower than 7%, but that target levels really should be based on benefits and risks of treatment based on patient comorbidities, life expectancy, and preference. Was that conclusion based on a summary of the evidence reviewed in the different guidelines, or was it an attempt to synthesize the recommendations that come from different guidelines?

A: It was more based on a summary of the guidelines. We did not review the evidence that went behind development of these guideline recommendations. So all the guidelines pretty much recommended individualized assessment of risk for the target A1c levels, but the target A1c levels differed from guideline to guideline. So we summarized the evidence in our guidance statement by saying that individualized assessment of risk is important, and an A1c target level of 7 is reasonable target for the majority of patients but not for all the patients.

Q: Given that many guidelines differed in their recommendations, do you have any advice for providers about how they should respond? Are there qualities of guidelines that they should be looking for that make one guideline better than another?

A: That is a very good question because there are several guidelines available on the same topic, and I think it’s really difficult for the practicing clinician to understand what went behind the development of the guideline as well as the evidence that was used to come up with the recommendation . So I would say there are certain critical elements to look for, such as if there were systematic methods that were used for the evidence review, and if the guideline is a consensus statement vs. if a guideline recommendation is based on evidence, and there is no external influence in coming up with the guideline recommendation. But the most important thing probably is to see if there is an explicit link between the evidence and the recommendation.

Q: And what’s an appropriate response when providers are held accountable to different quality standards that come from different sets of guidelines?

A: I think the most important thing for a physician to do is to take good care of the patients, keeping in mind the best available evidence, and keeping in mind the guidelines that are based on high quality evidence, such as evidence that’s derived from randomized controlled trials vs. the evidence that’s coming from consensus statements.

Q: And finally what else is the Clinical Efficacy Assessment Subcommittee working on that would be important for Annals readers to know about? What guidance statements and guidelines can Annals readers look forward to?

A: Currently we’re working on diagnosis and management of low back pain, as well as diagnosis and management of COPD. In addition we’re working on a guideline for end-of-life care. We are also working on an additional guidance statement that deals with primary prevention of stroke.

Q: Dr. Qaseem, thank you for talking to me.

A: Thank you.

That was Dr. Amir Qaseem, a Senior Medical Associate at the Department of Clinical Programs and Quality of at the American College of Physicians in Philadelphia, describing this week’s guidance statement on optimal HbA1c target levels.

Other articles in this week’s issue include:

A cross-sectional description of prescriptions filled at Kaiser Permanente in 2001, suggesting that prescriptions for potentially teratogenic drugs are frequently filled by women of childbearing age without documentation of contraceptive counseling.

An observational cohort study of almost 14,000 healthy adult men in the Israeli Defense Forces, confirming an association between elevated triglyceride levels and coronary heart disease, and suggesting that changes in TG levels over 5 years are associated with corresponding changes in the hazard of coronary heart disease

A meta-analysis of trials evaluating the prophylactic use of hematopoietic colony-stimulating factors, showing that use of the factors decreases episodes of infection in patients receiving chemotherapy or those undergoing stem cell transplantation but have only small if any effects on mortality

And we have an Update in Critical Care, the 4th of 10 Updates appearing this year based on presentations given at the American College of Physicians annual Internal Medicine 2007 session held in April in San Diego.

And Our On Being A Doctor essay this week is a brief account caring for patients seeking asylum in the US from physical and psychological torture in their countries of origin, and the effects of that torture on both patient and provider. It’s by Dr. Sandra Crosby of Boston Medical Center.

Well that’s it for this week. If you liked what you heard, of if you didn’t, tell us about it, at podcast{at}annals.org.

For full details of all of this week’s articles, please consult your print journal, or go to www.annals.org.

Technical support for this summary was provided by Andrew Langman, Neil Kohl, and Beth Jenkinson.

Special thanks to Kevin Stahl and all our friends at WHYY, public radio and television of Philadelphia, who helped produce this podcast.

Check back in 2 weeks for a complete summary of our regularly scheduled October 2, 2007 issue.

I’m Michael Berkwits, and thanks for listening.

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