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Update From the Medical Journals: March 2007
March 30, 2007  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. Over-the-Counter Pain Medicines May Promote High Blood Pressure Aspirin, ibuprofen (Advil, Motrin) and acetaminophen (Tylenol) are the three most frequently purchased over-the-counter medicines. A new study links frequent use of any one of these pain medicines by men to an increased risk for high blood pressure. (This study did not include women.) The study was published in the February 26 issue of the Archives of Internal Medicine. More than 16,000 male health professionals who had never been diagnosed with hypertension participated in the study. The men were surveyed every two years. After two surveys, the men were divided into groups based on how frequently they used any one of the pain medicines. At the end of the four-year study, the men were asked if they had developed high blood pressure. Compared with non-users, daily or near-daily acetaminophen users had a one-third higher risk of having hypertension. This meant that for every three men in the non-user group who developed high blood pressure, four men in the frequent-user group developed high blood pressure. The risk was also higher in groups that used ibuprofen or aspirin heavily. This study does not prove that the pain medicines caused high blood pressure for these men. Still, the study justifies some caution. These pain medicines can block chemicals known as "prostaglandins," and this can result in more tightly toned blood vessels. Ibuprofen or other non-steroidal anti-inflammatory drugs (NSAIDS) can cause retention of salt and water. These actions promote high blood pressure. While over-the-counter pain medicines are very useful, frequent use may have side effects. Back to top CT Screening for Lung Cancer Probably Doesn't Save Lives On March 7, the Journal of the American Medical Association (JAMA) published a study that examined whether yearly computed tomography (CT) scans could find lung cancers early, and if so, whether early treatment saved lives. This study looked at 3,246 current or former smokers who had CT scans of their lungs. The scans diagnosed three times more lung cancers than expected without CT scans. Ten times as many surgeries took place to remove small cancers. Yet, the experts concluded that doctors should not screen smokers with a CT scan. Why? Because even after studying their patients for an average of about 4 years, the number of people with advanced (metastatic) cancer and the number of deaths were no lower than usual. Aggressive lung cancers that are going to metastasize tend to do so within months after they first appear. So yearly CT scans aren't frequent enough to capture most of the cancers. This, the researchers point out, is probably why the number of advanced cancers did not change significantly, despite the large number of surgeries that took place. The authors believe that many of the cancers that are found are very slow growing. If we had a way to tell the slow-growing and fast-growing apart when we find them, these slow-growing cancers might not need treatment. Unfortunately, we can't tell by the look of lung cancer which way it will behave, even with a biopsy. Whether the cancer is an aggressive one or not, the mortality rate from surgery to remove lung cancer is about 5%. Doctors still disagree about the usefulness of CT scans for lung cancer screening. Another large study about this subject was published in October in the New England Journal of Medicine and was much more hopeful. It included more than 30,000 cigarette smokers, compared with the roughly 3,000 in the JAMA study. However, instead of total deaths, the October study looked at survival rates after CT screening. The survival rate after cancer diagnosis was longer, on average, in the group that was screened. However, survival rate can be a deceptive statistic because healthy people with small, slow growing cancers can bias the survival statistics merely because we are aware of their cancers for longer. Although lung cancer screening among smokers is still controversial, it is not currently recommended by most doctors. Back to top Sleeping Pills Have Surprising Side Effects On March 14, the U.S. Food and Drug Administration (FDA) issued new warnings about possible side effects of some commonly used sleep medications. The FDA also ordered manufacturers of 13 sleeping medicines to begin notifying doctors about the side effects, which only recently were identified. They include severe allergic reactions (anaphylaxis and tongue swelling) and also some curious behaviors that can occur during "drugged" sleep: sleepwalking, driving in your sleep, dialing and talking on the phone, and preparing and eating food. The medical term for these behaviors is "parasomnias." In your sleep, it is possible for you to get up out of bed, organize and complete a complicated task, yet remain unaware of what you are doing and not remember your actions later. These types of activities during sleep can result in serious injury due to accidents. Parasomnias occur when an area of your brain becomes active at inappropriate times in your sleep-wake cycle, as you move between different stages of sleep and wakefulness. It is not clear how many people who take sleeping medicines experience them. According to the FDA warning, the medicines that can cause these side effects include zolpidem (Ambien/Ambien CR), triazolam (Halcion), eszopiclone (Lunesta), estazolam (Prosom), temazepam (Restoril), ramelteon (Rozerem) , and zaleplon (Sonata), among others. Back to top More News in Brief - Second Dose of Varicella Vaccine is Now Recommended. Children are now routinely immunized against chicken pox (varicella). In June 2006, the Advisory Committee on Immunization Practices — the major group that advises the Centers for Disease Control and Prevention about vaccinations — advised that children should get a second dose of varicella vaccine between the ages of 4 and 6. The March 15 issue of the New England Journal of Medicine contained a study that supported this recommendation. The study investigated 11,356 cases of chicken pox (varicella) and found that the infection was more likely to occur in children who had only received one vaccination, particularly if the vaccine had been administered more than five years ago.
- Popular Weight-Loss Diets are Compared. A study in the March 7 issue of the Journal of the American Medical Association (JAMA), compared four popular weight-loss diets: the Atkins diet (very low-carb, high fat), the Zone diet (40% carbohydrates, 30% protein and 30% fat), the Ornish diet (70% carbohydrate but limited refined sugar, very low fat, vegetarian diet), and the "LEARN" diet (high carbohydrate, low fat, non-vegetarian diet that follows U.S. Dietary Guidelines). A total of 311 women participated in the 12-month study. They were randomly assigned to one of the four diets and given substantial support by a nutritionist in the first part of the year. Women in all four diets had difficulty following the specific diet plan through the year. Most women lost weight during the first six months of the study, then regained part of their weight back. At the end of the year, women assigned to the Atkins diet showed the largest amount of weight loss — 10 pounds on average. This study could not examine long-term risks or long-term weight-loss benefits of these diets, because the data collected were limited to one year.
- Obesity Surgery Can Cause Lasting Brain Disorder. An important complication of obesity surgery was reported in the March 13, 2007 issue of Neurology. It's called Wernicke's encephalopathy and while rare, 32 cases have been reported so far. Wernicke's disease results from a deficiency of vitamin B1 (thiamine). It causes wobbly walking, an inability to remember very recent events — even though long-term memory is preserved — and problems controlling eye movement leading to trouble focusing or double vision. Treatment with intravenous (IV) thiamine soon after symptoms appear can resolve symptoms in about one third of patients. For others, the damage and the symptoms are usually permanent. This complication is probably preventable by taking vitamin B1 supplements after surgery.
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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