| ||What Your Doctor Is Reading || |
Update From the Medical Journals: June 2012
June 29, 2012
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.
Calcium Supplements May Do More Harm than Good
An expert group may advise women not to take low-dose calcium supplements with vitamin D. They increase the risk for kidney stones and do not protect bones from fractures. In separate news about calcium supplements, heart attacks might be more likely in women who take calcium.
Many doctors recommend calcium supplements to women for their bone health. In fact, the Institute of Medicine has recommended calcium supplements for years. But the U.S. Preventative Services Task Force (USPFTF) announced online June 12 that it is preparing a new recommendation telling women not to take calcium and vitamin D, at least in low doses. The task force says it will take a closer look at hig-dose supplements. Low-dose supplements put women at risk for forming kidney stones, but they don't reduce fractures enough for us to detect a benefit in studies. So they do more harm than good.
A study published online on May 23 in the journal Heart had its own warnings about calcium. Researchers divided 23,980 people into several groups depending on how much calcium their diets had. They also looked at people who took calcium supplements with and without vitamin D. The researchers didn't see any difference in heart attack or stroke rates based on how much calcium people got from dietary sources. But calcium pills seemed different. The researchers looked at medical events over 11 years. They found a higher rate of heart attacks in people taking calcium supplements compared with people who did not take supplements. The extra risk was particularly bad for people who took calcium without vitamin D. They had more than doubled the heart attack risk.
Compared with calcium in food, calcium in pill form can put a high concentration of calcium into your bloodstream quickly. Too much calcium in the blood at one time can harden your arteries, experts think.
The idea that heart attacks might be more likely in people who take calcium is not new. A heart attack risk was proposed in a British Medical Journal study in 2010. But the risk seen in this new study was much higher than previously thought. The USPSTF is watching this new research and allowing doctors to send in comments before making their recommendations about calcium supplements final.
What should you do now? The news about calcium is disappointing. Many of us thought calcium supplements were part of good health. All women should make sure to get plenty of calcium in foods. If you are being treated for osteoporosis (thin bones) it is also reasonable to continue calcium and vitamin D supplements in doses recommended by your doctor. For most other women, calcium supplements can be put on the back shelf until more information is available.
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Statin Drugs May Not Help Women Live Longer
Cholesterol-lowering drugs called statins can help men live longer by preventing heart attacks. Women have fewer heart attacks than men. And according to new research, the drugs may not be as beneficial to their hearts.
The Archives of Internal Medicine published an analysis of 11 different studies of statin drugs on June 25. The combined studies included 43,191 people. Based on this huge number of people, researchers could see that heart attacks, other heart events (such as a need for a stent or surgery), strokes and early death were less likely to occur in the groups that had men and women who took statins. But when men were separated from women, researchers did not find fewer premature deaths among the women. There was no difference in "all-cause mortality" for women during the study period. There was also no difference in the risk for stroke in women who took a statin.
This study has received a mixed reaction. Critics of the study say there were not enough women studied to give us accurate information about the benefits of statins. (Fewer than 10,000 women were in the combined studies).
Nonetheless, if there is a survival benefit or stroke benefit from statin drugs for average women, it's likely to be small. Women who have already had a heart attack do have a lowered future heart attack risk if they take a statin. The National Cholesterol Education Program (sponsored by the National Heart, Lung, and Blood Institute) is expected to update recommendations for statin use and cholesterol treatment this year. They will need to take this analysis into consideration when they decide whether to make the same recommendations for men and women.
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More News in Brief
- Childhood Cancer Survivors Should Start Colon Cancer Screening Early. A study in the June 5 issue of the Annals of Internal Medicine looked at the rate of colon cancer and other digestive tract cancers among 14,358 childhood cancer survivors. It found that children and young adults who had received abdominal radiation or chemotherapy have five times the usual risk for getting a digestive tract cancer later in their lives.
Often, colon cancer appears at a surprisingly early age in adults who had childhood cancer treatment. According to the Children's Oncology Group, most people who had radiation treatments as a child should start getting screened for colon cancer (usually with a colonoscopy exam) by age 35. This new study suggests that an early start to colon cancer screening is appropriate for people who had chemotherapy as children, as well.
- Hyaluronate Knee Injections Don't Help Arthritis. Injections of hyaluronate, a material that is a building block for cartilage, have been used as a treatment for age-associated arthritis (osteoarthritis). A comprehensive analysis of 89 studies found that the injections had little or no effect on pain. And they didn't improve knee function. Some of the studies showed an increased risk for side effects such as "flare-ups" of pain and knee inflammation. The study was published online June 11 by the Annals of Internal Medicine. Familiar brands of hyaluronate include Hyalgan, Synvisc, Supartz, Orthovisc and Euflexxa. With this disappointing summary of results, these treatments are unlikely to be offered in the future.
- More than 13 Million Americans Have Survived Cancer. The American Cancer Society and the National Cancer Institute are reporting good news: More people are surviving cancer. This is because of early diagnosis and more effective treatments. Forty-five percent of cancer survivors in the United States are 70 years old or older. This update was published online by CA: A Cancer Journal for Clinicians on June 14.
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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.