Preventing Recurrent Ulcer Bleeding
Rather than clopidogrel, aspirin plus a proton-pump inhibitor should be prescribed to prevent recurrent bleeding from ulcers in high-risk patients, according to results of a double-blind, randomized trial.
Francis K.L. Chan, M.D., of the Chinese University of Hong Kong and his associates reported that recurrent ulcer bleeding occurred at a significantly higher rate in 161 patients who received clopidogrel (Plavix) plus a placebo than in 159 patients who received aspirin plus esomeprazole (Nexium) during a median follow-up of 12 months (8.6% vs. 0.7%). Patients took either 75 mg clopidogrel daily or 80 mg aspirin daily plus 20 mg esomeprazole twice daily (N. Engl. J. Med. 2005;352:238-44).
The study included patients who had endoscopically confirmed ulcer healing, had negative tests for or successful eradication of Helicobacter pylori and were not taking anticoagulants or corticosteroids. Study participants had presented with upper GI bleeding after taking low-dose aspirin for prevention of vascular diseases.
The results go against American College of Cardiology/American Heart Association guidelines that advise using clopidogrel as an alternative antiplatelet agent for patients with major GI intolerance of aspirin, he noted. The study “clearly indicates that this recommendation is harmful and that such patients should be given aspirin plus a proton-pump inhibitor,” said Byron Cryer, M.D., of the University of Texas Southwestern Medical Center, Dallas, in an editorial. Antiplatelet agents may cause bleeding ulcers primarily by impairment of healing (N. Engl. J. Med. 2005;352:287-9).
Colorectal Adenoma Chemoprevention
Calcium supplements appear to reduce the risk of developing recurrent colorectal adenomas, according to findings from a metaanalysis of three randomized controlled trials.
In 1,279 patients aged 35-76 years who completed a follow-up colonoscopy after 3-4 years, supplemental calcium (1,200 mg, 1,600 mg, and 2,000 mg daily in the three studies) significantly reduced the risk of recurrent adenomas by 20%, compared with placebo. The patients had a dietary calcium intake ranging from 940 mg to 1,600 mg, reported Aasma Shaukat, M.D., of the State University of New York, Buffalo, and colleagues (Am. J. Gastroenterol. 2005;100:390-4).
Calcium is thought to decrease the risk of recurrent adenomas by binding to and precipitating bile acids and soluble fatty acids. The results of the metaanalysis suggest that recommending a calcium supplement to patients with prior adenomas is a reasonable strategy for achieving a modest decrease in future adenomas. Calcium is cheap and safe, and only about 14 patients need to be treated to prevent 1 patient from having recurrent polyps during a 3- to 4-year period, said Robert S. Sandler, M.D., of the University of North Carolina, Chapel Hill, in an editorial (Am. J. Gastroenterol. 2005;100:395-6).
Colorectal Ca Risk and Eating Meat
High intake of red or processed meat over long periods of time is associated with an increased risk of cancer in the distal colon, rectosigmoid colon, or rectum, reported Ann Chao, Ph.D., of the American Cancer Society, Atlanta, and her associates.
The prospective study included data obtained from about 149,000 men and women who completed a questionnaire in 1982 for the Cancer Prevention Study II and then completed a follow-up questionnaire in 1992 or 1993. Men and women who consumed the most red meat during 1992-1993 had a significant, 71% increase in their risk of cancer of the rectosigmoid colon or rectum. The risk increased progressively from lower to higher intakes of red meat (JAMA 2005;293:172-82).
Men and women who consumed large amounts of processed meats (preserved by salting, smoking, or addition of nitrites or nitrates) in 1982 and in 1992-1993 had a significant, 50% increase in risk of cancer in the distal colon, compared with people who consumed low amounts of processed meats during both periods.
Magnesium and Rectal Ca Risk
Higher magnesium intakes are associated with decreased risk of rectal cancer in women, reported Susanna C. Larsson of the Karolinska Institute, Stockholm, and her colleagues.
After a mean follow-up of nearly 15 years, women with magnesium intakes in the top quintile (at least 255 mg/day) had a rectal cancer risk that was 55% lower than the risk in women with magnesium intakes in the bottom quintile (less than 209 mg/day). Risk reductions were 52%, 46%, and 36%, respectively, in the second-highest, third-highest, and fourth-highest quintiles. The prospective study included about 61,000 women in the Swedish Mammography Cohort who completed a questionnaire between 1987 and 1990 and a second questionnaire in 1997 (JAMA 2005;293:86-9).