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Update From the Medical Journals: February 2008
February 29, 2008  By Mary Pickett, M.D.
Harvard Medical School What's the latest news in the medical journals this month? Find out what your doctor is reading. Blood Sugar: How Low Is Too Low For Adults With Type 2 Diabetes? The National Heart, Lung, and Blood Institute announced in a press release on February 6 that it had stopped one part of a very large diabetes study 18 months early. Adults with type 2 diabetes received treatment to lower blood glucose (sugar) below current recommendations. This unexpectedly increased their risk of death compared with people who received a less-intensive standard treatment. Prior studies suggested that reducing blood sugar to levels found in non-diabetic adults may reduce the rate of some cardiovascular problems, such as heart attack, among people with diabetes. But there had been no studies large enough to detect an effect on survival until now. This study, called the ACCORD trial, involved 10,251 middle-aged and older adults with diabetes who also had atherosclerosis or risk factors for atherosclerosis. Blood-sugar averages were monitored using blood tests for hemoglobin A1C, a common diabetes monitoring test. The participants were randomly assigned to receive either intensive blood glucose-lowering treatment with an A1C goal of less than 6%, or standard treatment with an A1C goal of 7% to 7.9%. The latter target goal is slightly more liberal than what the American Diabetes Association advises — an A1C less than or equal to 7%. The first target goal would require nearly-normal blood sugars for diabetics. There have been 257 deaths in the intensive-treatment group over an average of four years of treatment (ranging from about 2 years to about 7 years). The group receiving standard treatment has had 203 deaths. This means that the risk for death was about 20% higher for those with a target blood-sugar goal of less than 6%. Many of the deaths appeared to be fatal heart attacks or strokes. The risk for a heart attack or stroke did not seem to be higher when non-fatal and fatal events were considered together. However, the risk for a fatal event did seem to be higher. The diabetes medications used in the study include metformin, rosiglitazone (Avandia), insulin injections, sulfonylureas (for example, Glipizide), exanatide (Byetta) and acarbose (Precose). Because there have been recent concerns that rosiglitazone might increase the risk for heart attacks, researchers looked carefully to see if the extra deaths could be explained by more frequent use of this medicine. They found no obvious link between the extra deaths and rosiglitazone — or any other study medication. The people in this study are still being monitored. Everyone will now receive the less-intensive standard treatment. Within the next two years, researchers are hoping to have data showing how different cholesterol-treatment strategies and blood-pressure goals are affecting the participants. (The researchers have also been tracking these data in the study and will analyze each health issue separately. Good blood-sugar control lowers the risk for damage to the eyes, kidneys and nerves. It can lower the risk for heart attack and stroke. This study asked the question, "How low can you go?" The answer appears to be "not so low that your A1C is near normal," if you have type 2 diabetes and have an especially high heart-disease risk. Based on previous study data, near-normal A1C levels are still the best goal for people who have type 1 diabetes, as long as hypoglycemic (low blood sugar) spells don't make that goal difficult to reach. Back to top Prostate Cancer Treatments Are All Effective Currently, about one out of every five men will be diagnosed with prostate cancer during his lifetime. The risk of dying from prostate cancer is only 3%, but there is a high risk for side effects from treatments. On February 5, the Annals of Internal Medicine released a comprehensive review online comparing common treatments for prostate cancer that had not spread beyond the prostate. (It will appear in the printed journal March 18.) This review was commissioned by the Agency for Healthcare Research and Quality. Researchers analyzed data from 491 published studies. They included the following treatments in the comparison: surgery (open prostatectomy, laparoscopic or robotic prostatectomy), external-beam radiation, implantation of radioactive beads (brachytherapy), freezing (cryotherapy), high intensity ultrasound treatment and androgen deprivation (with hormone medicines or testicle removal). "Watchful waiting" strategies, including those that involved periodic biopsies and testing, were also considered. (Watchful waiting involves waiting until the cancer appears to be changing before treating it surgically or non-surgically. The data were difficult to interpret. Only a few of the studies about prostate cancer treatment have been randomized studies – the gold standard. Studies that are not randomized have less reliable results. Because some of the studies that were included took place before the prostate specific antigen (PSA) blood test was commonly used as a screening test for prostate cancer, there were many men among those studied whose cancers were discovered by a physical exam, or found because they began to have symptoms. This makes it difficult to apply the findings of these studies to the typical man who has prostate cancer today, because the PSA test finds most cancer in a very early stage. Another challenge for the reviewers was the different ways the various studies defined side effects. This makes it difficult to combine information and make comparisons. Prostate cancer has a low mortality rate, so it was impossible to say from the analysis whether one treatment improved survival more than another. In fact, the authors could not even conclude that any of the treatments has a survival advantage over "watchful waiting." They acknowledged that many of the studies did not follow patients long enough to adequately compare treatments and watchful waiting. Combining androgen deprivation treatment with surgery creates more side effects and does not measurably improve the odds of survival. Combining radiation and androgen deprivation treatment seems to slightly improve survival, but again, side effects are more likely. All of the treatments for prostate cancer caused side effects. (As you might expect, watchful waiting had the fewest side effects reported.) The most significant side effects were urine leakage, inability to have erections and bowel irritation. Some of the most reliable data showed that about 35% of men who were treated with surgery had urine leakage. This is about three times the rate that occurred with radiation treatments or androgen deprivation. Bowel urgency was a rare side effect of surgery. It occurred in 3% of people with external-beam radiation or androgen deprivation. More than half of men treated with surgery and almost all men treated with androgen deprivation had sexual function side effects. The lack of guidance provided by this large review is frustrating. It shows that there is a need for randomized studies to compare prostate cancer treatments. Still, this review reassures patients that their risk of dying from prostate cancer is low, no matter which treatment option they choose. Another reassuring finding is that more than 90% of patients who had been surveyed about their treatment report that they would make the same treatment decision again. Also, most men were either delighted or pleased with their treatment decision. Men who chose not to wait before selecting a treatment were more satisfied than men who chose watchful waiting before a treatment. Back to top More News in Brief - Obesity Surgery Sends Newly-Diagnosed Type 2 Diabetes Into Remission – According to a study in the January 23 issue of the Journal of the American Medical Association (JAMA) obesity surgery can send type 2 diabetes into remission, if the surgery is done within the first two years of diagnosis. This study included 55 obese adults with newly diagnosed diabetes who were between 20 and 60 years old. They were divided randomly into two groups. The members of one group met individually with a dietitian, nurse, diabetes educator or physician every six weeks or more often throughout the two-year study period. Each person received diabetes medication, diet advice, and a specific exercise program. The members of the other group received these same counseling and treatment interventions, but they also had laparoscopic gastric banding surgery. The procedure involves placing an adjustable ring around the stomach to limit eating and facilitate weight loss. The surgically treated group lost an average of 21% of their body weight, while the other group lost less than 2% on average. Two years after the treatment, 73% of the surgically treated group (22 out of 29 patients) had fasting glucose levels less than 126mg/dL without medicines. Their A1C levels were less than 6.2% or close to normal. For these patients, type 2 diabetes was considered to be "in remission." Only 13% of the group that did not have surgery had a remission of their diabetes at the two-year evaluation. This study is small, but it is remarkably important. It is likely that diabetes care guidelines will soon include discussion about obesity surgery as a potential treatment for type 2 diabetes. How long type 2 diabetes stays in remission is unknown. This study only included people who were newly diagnosed. It is less likely that a person who has had diabetes for many years would have a remission after surgery, but this will be an important question for additional study. Losing weight and maintaining the loss after obesity surgery requires a long-term effort by the individual to limit calorie intake and remain physically active.
- New Strategy Gives Hope for Organ Transplants Without Toxic Medications – A study in the January 24 issue of the New England Journal of Medicine describes an exciting new idea that may spare future organ transplant patients from taking medicines that suppress the immune system. Five people who had kidney failure but had healthy bone marrow were treated with drugs to suppress their bone marrow. Then they were given a bone marrow and kidney transplant using the same donor. So far, four out of five of the recipients of the double transplants have been able to wean off their immune suppressant medicines without rejecting their donated organ. The patients' immune systems appear to have features of both the old immune system and the new (donated) bone marrow. Rejection does not seem to occur during the first few years after a transplant. If additional research can perfect this technique, it may be a major advance for organ transplants.
- Birth Control Pills Lower Long-Term Risk for Ovarian Cancer – An analysis of previous studies found that women who took birth control pills were less likely to get ovarian cancer decades later, although the overall risk was small with and without the birth control pills. The results were published in the January 26 issue of the Lancet. Researchers pooled or combined all of the data so they could analyze the experience of more than 23,000 women with ovarian cancer, and compare it to 87,000 other women who were similar in age, but cancer-free. For every 5,000 women who use birth control pills for one year, about two cases of ovarian cancer and one death as a result should be prevented.
- Obesity Increases Cancer Risk – The February 14 issue of Lancet published a report based on data from 141 previously completed studies linking various cancers and body weight. The researchers concluded that obesity increases the risk of cancer of the esophagus, thyroid, kidney, uterus and gall bladder. By combining data from so many studies, the researchers included nearly 300,000 cases in their analysis. We've known that excess weight is associated with an increased risk of colon cancer and breast cancer. Now we know that obesity is linked to other cancer as well. Weight gain of about 30 pounds within 15 years was linked to the higher cancer risk.
Back to top Mary Pickett, M.D. is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University. At OHSU, she is a director of student programs and she oversees teaching of students and medical residents. She practices general internal medicine in Portland, Ore.
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