 | What Your Doctor Is Reading | | |
Update From the Medical Journals: July 2009
July 31, 2009  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. Anti-Acid Drugs Can Lead to "Rebound" Symptoms About 5% of people from developed nations take a potent acid-blocking medicine to treat acid reflux or digestive symptoms. Are you one of them? If so, you will surely be interested in a study published in the July issue of Gastroenterology. The study shows that anti-acid medicines can cause the very symptoms that they are used to treat. The "rebound" symptoms occur after the drug is stopped. The study included 120 healthy adults who did not have any acid reflux symptoms at the beginning of the study. They had not been taking anti-acid medicines. They were randomly assigned to two months of treatment with esomeprazole (Nexium) or placebo treatment. About one week after stopping the medicine, 44% of people who had been treated with the acid-blocking drug began to develop new symptoms. They included heartburn, acid reflux, abdominal discomfort, or more than one symptom. Only 15% of the people who who received placebo pills reported similar symptoms. It was typical for the new symptoms to last for at least two weeks. However, the the study did not collect symptom reports after this, so the total time people had symptoms was not known. Why would these new symptoms follow treatment with an anti-acid drug? Your stomach changes when you take anti-acid medicine. It adds new acid-producing pumps in its lining cells to "fix" its acid shortage. Any acid-blocking medicine can keep the old and new pumps turned off. But when the drug is stopped, acid production can increase. It takes a while for your stomach to dismantle the new acid-producing pumps. This is not the first research to show the acid "rebound" effect. But this new study is the most dramatic illustration of the problem. Previous research has shown rebound acidity after two weeks of treatment. Studies have found that rebound symptoms from proton pump inhibitors, our most potent anti-acid drugs, may last up to two months. Proton pump inhibitors include omeprazole (Prilosec, Prilosec OTC), esomeprazole (Nexium), lansoprazole (Prevacid), pantoprazole (Protonix, Pantoloc) and rabeprazole (Aciphex). Other research has suggested that rebound symptoms from milder medicines called H2 blockers can start about two days after stopping the drug. But they end much sooner, about 10 days after stopping. Examples of H2 blockers are ranitidine (Zantac), cimetidine (Tagamet), nizatidine (Axid) and famotidine (Pepcid). Does this study mean that you can't stop one of these drugs once you have started it? No, but be aware that you may have symptoms for a while when you do stop. Some people restart the medicine because of symptoms. If you do take a break from your medicine, consider waiting a while without treatment to see if you truly need it. This study makes it clear that doctors should limit proton pump inhibitors to people who clearly need them. It may be best to start with lower strength medicines (for example, an over-the-counter antacid such as Tums, Mylanta, Maalox or Rolaids). Back to top CRP and Similar Blood Tests Don't Add Much in Predicting Heart Disease The July 1 issue of the Journal of the American Medical Association (JAMA) included two new studies about blood tests that might (or might not) predict your heart risk. Both studies have made these tests look a lot less helpful than some experts had hoped would be the case. The first study looked at a blood test named C-reactive protein (CRP). The blood contains more of this protein when there is inflammation inside blood vessels. People with extremely high CRP have three times the normal risk of heart attacks and double the normal risk of stroke. But does CRP play a role in causing a heart attack? This study looked at CRP blood studies and genes of 28,112 people who either had a heart attack or had an artery opened to prevent one. Their test results were compared with those of 100,823 people who did not have heart events. The study did not point to CRP as a cause of heart attacks. Instead, it appeared from this research that high CRP levels run in families. The study results also seemed to show that high CRP levels were the result of artery disease, not the other way around. The second study looked at a handful of blood tests known as "biomarkers." They included CRP and several other tests that have not been as well known. They are abbreviated as N-BNP, cystatin C, Lp-PLA2, MR-proADM, and MR-proANP. Experts have hoped that biomarkers could make predictions of heart disease risk more accurate. In the study, more than 5,000 people with an average age of 58 had biomarkers measured. Researchers kept track of the people for 10 to 15 years. The biomarker tests did relate to heart disease, but not very closely. They added very little information to the factors — such as smoking and family history — that already are used to predict risk. For example, doctors would have been alerted to manage cholesterol levels more closely for only 1% of people in the study, if they considered biomarkers as well as other risk factors. To calculate your heart risk, your doctor should stay with the big five risk factors: - Smoking
- Cholesterol levels
- High blood pressure
- Family history
- Presence or absence of diabetes
Lack of exercise and obesity are also known to predict heart risk. So are health problems such as rheumatoid arthritis and psoriasis, which cause lasting inflammation. In general, measuring blood biomarkers is neither necessary nor helpful. Back to top More News in Brief - People With Type 1 Diabetes Are in Better Health Than Ever. A study in the July 27 issue of JAMA gives an update on the kind of life and health that people with type 1 diabetes can expect. Before insulin injections were available, this was a quickly fatal disease. With insulin, people with type 1 diabetes could survive for years. But many developed blindness, kidney failure, heart attacks at a young age, and foot ulcers that required amputations.
During the last 20 years, doctors have begun to control blood sugar levels much more tightly than they did in the past. Today, with intensive insulin treatment, only 22% of people with type 1 diabetes have needed treatments for retina disease in their eyes by the time they have had the disease for 30 years. Just 1% or fewer go blind. Only 9% have partial kidney failure after 30 years of diabetes. Fewer than 1% require regular dialysis. About 9% develop heart disease. Fewer than 1% of type 1 diabetics need an amputation in their first 30 years. Tight control of glucose, beginning early in the course of diabetes, has paid off with much better health outcomes.
- Numbers of Elderly Are Increasing at Fast Pace. The National Institute on Aging released a new report July 20 about the aging of our population. This report made stunning predictions about the unprecedented changes that are occurring in the age distribution for our communities. By 2040, researchers expect that 14% of the U.S. population will be older than 65. That's up from 7% now. Experts think the number of people aged 80 and older will more than triple. About 1 out of 5 U.S. women who were ages 40 to 44 in 2006 did not have any children. Our communities will need to find ways to care for elderly people who cannot rely on families. The census report and predictions are published online.
- For Best Results in Bypass, Surgeons Need a Direct View. Normally, less invasive ways of doing surgery are a good thing, and healing is more efficient. However, this might not be true for harvesting blood vessels used in heart bypass surgery. A new report on this is in the July 16 issue of the New England Journal of Medicine. About 3,000 patients at 100 American medical centers were watched in the study.
An unexpectedly high number of deaths and heart attacks occurred in the years after surgery for people who had leg veins removed using the newer technique, endoscopy. This is less invasive and requires a smaller cut than the older method. Deaths or heart attacks occurred for more than 9% of people who had leg veins removed endoscopically. They occurred for fewer than 8% of people who had veins removed with the older technique. It may seem small, but this difference is meaningful. It was also a surprise. The less invasive technique was expected to show better results, not worse. Endoscopy seems to cause less damage in the leg at the time of vein harvest. However, the vein may be damaged by instruments and removal through the narrow incision in this surgery. This study should change surgical plans for many bypass operations.
Back to top Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications. | |
