Update From the Medical Journals: February 2013
February 28, 2013
By Mary Pickett, M.D.
What's the latest news in the medical journals this month? Find out what your doctor is reading.
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) published a new recommendation February 26 telling women not to take calcium supplements with vitamin D, unless they have osteoporosis or a previous fracture. The recommendation was published in the Annals of Internal Medicine.
The task force says that the evidence is now clear that typical doses of the supplements do more harm than good to women after menopause. The evidence was not as complete for women before menopause and for men. But for now, the task force does not see a strong reason to recommend supplements for these groups either.
Low daily doses 400 IU of vitamin D and 1,000 milligrams of calcium) increase the risk of kidney stones. And studies using these doses don't detect a benefit for reducing bone fractures. Higher doses may lower fracture risk, but it is hard to be sure that this benefit outweighs the risks that come from treatment.
Another study about calcium supplements shows that they may increase heart disease risk. JAMA Internal Medicine published the study online February 4. Calcium from pills gets into your bloodstream faster than calcium from food. Too much calcium in the blood at one time can harden your arteries, experts think.
This study followed 388,000 men and women over 12 years. Of this group, 51% of men and 70% of women were taking calcium pills. Men who took 1,000 milligrams of calcium daily had a 20% increased risk of heart-disease death. There was no visible increase in risk for women who were taking calcium pills. Calcium in the diet (for example, the amount of dairy products consumed) did not affect death risk for men or women.
This news about calcium is disappointing. Many of us thought calcium supplements were part of good health. Everyone, especially women and children, should try to get plenty of calcium in foods. That hasn't changed. Research shows that vitamin D helps prevent falls. Vitamin D (without calcium) is recommended for people who are at risk for falls. If you are being treated for osteoporosis (thin bones) or have a previous history of fracture, you should take both calcium and vitamin D supplements in doses recommended by your doctor. For most other women and men, calcium supplements are not recommended.
A surgical treatment for Parkinson's disease called deep brain stimulation or neurostimulation has helped reduce some symptoms of the disease when it's in the advanced stages. A study published February 14 in the New England Journal of Medicine shows that the treatment may also be useful for people who are in earlier stages of the disease.
Parkinson's disease causes tremors in the hands and head. At the same time, purposeful movements such as walking and reaching can be difficult to initiate. These symptoms can be treated with medicines. Unfortunately, the medicines cause side effects and don't always relieve symptoms completely.
During deep brain stimulation an electrode on a wire is placed into a specific location in the brain. Electric pulses are generated, similar to a pacemaker. These reset the electric current in the brain. This seems to improve overall function for people with Parkinson's.
This study included 251 people in the early stage of Parkinson's. They were randomly divided into two groups. One group received deep brain stimulation surgery and medications, if needed. The other group received only medications. After two years, patients were asked about their symptoms. The group that had surgery could move more easily and could better manage their activities of daily living. However, there were more side effects in the group that had surgery. Most of these problems were short term, such as infections related to the surgery. In some cases the stimulator had to be removed. Other side effects from the stimulator included falls, walking or balance difficulty, and uncoordinated or uncontrolled movements. Depression scores were improved overall in the group that had surgery, but the researchers were concerned to see that there were more suicides in the surgically treated group. This was unexpected.
We need to be cautious about using this aggressive treatment in people who are in the early stages of Parkinson's disease. This study only included people who were under 60 years old, who did not have Parkinson's-related dementia, and who were otherwise healthy. We can expect older people to have more complications. But this study provides hope to Parkinson's patients who wish to consider deep brain stimulation as a possible treatment. The treatment seems to improve quality of life, although complications are fairly frequent. Doctors don't yet know the long-term results for this treatment.
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.