H. pylori Infection May Aggravate GI Injury in Patients Taking Low-dose Aspirin
Doctors commonly prescribe low-dose aspirin for the prevention of heart disease, but it may also be responsible for some potentially serious side effects when taken frequently. Among the most common of these are gastrointestinal erosions and ulcers.
A recent study in The American Journal of Gastroenterology sought to determine whether certain people taking low-dose aspirin specifically, people infected with Helicobacter pylori, a common bacterium that can cause ulcers are more susceptible to gastrointestinal erosions and ulcers than people who are not infected with H. pylori.
Researchers from the University of Texas Southwestern Medical School and Baylor College of Medicine recruited 61 healthy volunteers between the ages of 18 and 61. Of these, 29 volunteers were infected with H. pylori. Forty-six of the volunteers were then randomly selected to receive low-dose aspirin (either 81 mg daily or 325 mg every three days), while 15 received a placebo.
After 46 days of treatment, an upper GI endoscopy was performed on each subject to determine the extent of gastrointestinal injury. The researchers did not detect any injury in the stomach or duodenum (upper intestine) of the patients taking placebo. In the subjects taking aspirin, those patients who were infected with H. pylori were significantly more likely to have gastrointestinal injury than those who were not infected (50% vs. 16%).
However, there was no difference between the groups in complaints of pain, nausea, vomiting, indigestion, or heartburn. In addition, the difference in outcomes between patients taking 81 mg of aspirin daily and 325 mg every three days was not statistically significant.
The researchers caution that the results of this study may not hold for older people or those with gastrointestinal diseases such as peptic ulcer disease, because the volunteers were healthy and aged 61 or younger. However, this study does suggest eradicating H. pylori infection may help prevent gastrointestinal erosions and ulcers in patients taking low-dose aspirin on a long-term basis.
October 2001 Update
Chronic myelogenous leukemia (CML), one of four main types of leukemia, strikes about 5,000 people every year. On average, patients live 3-4 years after receiving a diagnosis of CML. Last week, the FDA approved Gleevec (imatinib mesylate, also known as STI 571) as an oral treatment for CML.
Gleevec has been shown to substantially reduce the level of cancerous cells in the bone marrow and blood of treated patients. In clinical trials, 90 percent of patients in the first phase of CML went into remission within the first six months of taking Gleevec. Of patients in the second phase of CML, 63 percent went into remission with Gleevec. The drug produced few side effects.
Additional studies need to be done to determine how long the effects of this drug last, whether patients become resistant to the drug, and, most importantly, whether Gleevec can actually extend a patient's life.
Still, the results are promising. Currently, the only cure for CML is a bone marrow transplant. Even if a patient is lucky enough to find a marrow donor match, the procedure is successful less than 2/3 of the time. Interferon, a widely used treatment for CML, can extend a patient's life for up to two years, but it has several serious side effects and does not cure the disease. Gleevec may be used in patients in the early stage of CML who do not respond to interferon therapy, and in patients in the later stages of CML.
Most people with CML have a chromosomal abnormality, known as the Philadelphia chromosome, in which portions of two different chromosomes are switched. The result is the creation of an abnormal protein that allows the uncontrolled production of white blood cells, which can interfere with the function of other organs in the body. Gleevec blocks a signal sent out by the abnormal protein, thus blocking the rapid growth of white blood cells.
The FDA's approval of the drug came after a surprisingly short 2½ months. Most drugs that, like Gleevec, are granted a priority review, take six months to approve. The approval was based on three separate studies that involved about 1,000 patients with CML. The drug has generated enthusiasm in the medical community because it targets a specific, cancer-causing protein, without damaging other cells.
Scientists at an American Society of Clinical Oncology meeting announced earlier this month that Gleevec had also produced remission in 180 patients with advanced cases of an intestinal cancer known as gastrointestinal stromal tumor (GIST). Until now, GIST cancers have been incurable; GIST patients normally die within one year of receiving their diagnosis.
May 2001 Update
Celiac disease (pp. 774777) has an excellent Web site that will lead you to much good information: www.celiac.com.
Young Men and Women with Anorexia Nervosa or Inflammatory Bowel Disease at Greater Risk for Osteoporosis
We usually think of osteoporosis as a condition that primarily strikes older women as a result of the aging process. However, certain disorders and medications can also lead to bone loss in younger people, both male and female. Two recent studies from the Annals of Internal Medicine show that bone loss is significantly more likely to occur in young men and women suffering from anorexia nervosa or inflammatory bowel disease than in the general population.
Researchers evaluated the loss of bone tissue in women with the eating disorder anorexia nervosa by measuring bone mineral density at different regions of the skeleton. More than 90% of the women had significant bone loss at one or more skeletal regions. Depending on the region measured, this bone loss put 1324% of the women at risk for fractures. Physicians commonly prescribe estrogen to slow bone loss in postmenopausal women. Estrogen is also given to women who do not menstruate regularly, which is the case for many women with anorexia. Interestingly, in this study, women who used estrogen experienced the same levels of bone loss as women who did not. The researchers theorized that poor nutrition might decrease the effectiveness of estrogen in preserving bone. The results also showed that current weight, independent of other factors, is the best predictor of bone density in anorectic women.
In a separate study, researchers sought to determine the risk of bone fractures associated with osteoporosis in patients with inflammatory bowel disease. Results of the study showed that patients with the disease had a 40% greater risk of hip, spine, wrist, or rib fractures than healthy people. Researchers are still uncertain what factors contribute to bone loss in these patients. They speculate that corticosteroids, which are used to treat inflammatory bowel disease, may play a role, and that cigarette smoking, lower levels of sex hormones, and low dietary intake of calcium and vitamin D may also contribute to bone loss.