Update From the Medical Journals: February 2011
February 28, 2011
By Mary Pickett, M.D.
What's the latest news in the medical journals this month? Find out what your doctor is reading.
People who eat a high-fiber diet live longer, according to a study published online February 14 by the Archives of Internal Medicine. Researchers surveyed the dietary habits and health of 388,000 men and women over age 50 for nine years. People were divided into one of five groups based on how much fiber they ate regularly. The group with the highest fiber consumption had 22% fewer deaths during the study years compared with the group with the lowest fiber intake. This difference was found after taking into account differences in weight, educational background, smoking and common chronic diseases.
Fiber is a part of fruits, vegetables, grains (bread, cereal) and beans that we can't digest. It has no calories and just passes out of us. But fiber carries with it important vitamins and minerals. It moves our digestion along at a faster pace, helping us to eliminate other non-digestible things (like carcinogens) more quickly.
In this study, fiber appeared to be good for heart health and the immune system, and was even helpful in lung disease. The best fiber seemed to be from whole grain foods. It is a great idea to increase the number of fiber-containing foods in your diet. The men in the "high-fiber" group in this study averaged 29 grams a day; the women averaged 26 grams a day. But change your fiber slowly, because your digestive system will need to gradually adjust.
Heart failure can limit a person's physical activity or cause occasional fatigue. During a flare-up, heart function worsens. This can lead to leg swelling, breathing distress and sometimes a hospital stay. When an episode occurs, ajusting heart medicines such as diuretics can help people to improve. These adjustments work best when the flare-up is identified quickly.
Now, promoters of a surgically implanted monitor say their device can alert doctors early in a heart failure episode. Their study, published online February 9 by Lancet, randomly assigned 270 patients with symptomatic heart failure to either receive the device or not. The study then compared the two groups. Remarkably, those with the device had 30% fewer hospital stays in the first 6 months of the study, and 39% fewer stays for those patients who were tracked longer.
The implantable monitor (called a "hemodynamic" monitor) is still experimental. It is designed to detect a change in pressure that occurs in the early stages of a heart failure flare. This monitor measures pressure where the right side of the heart empties blood into the arteries of the lungs. A high pressure suggests that the left side of the heart is falling behind in its work. The monitor is a little larger than a silver dollar. It is surgically placed in the chest wall near the left shoulder similar to a pacemaker. A wire about 12 inches long from the device goes through the wall of a large vein in the chest, into the superior vena cava, and into the right side of the heart. A person can use a telephone-like device to "download" information from the device, which can be transmitted to a central analyzing location. If a pressure change is detected, a doctor can make changes to a patient's medicine before the patient has noticed symptoms.
This implantable system depends on patients regularly downloading their data in order to get benefits. In my experience, heart failure patients who weigh themselves daily and call to report small changes in their weights are also able to quickly identify the times when they need extra medicine for their heart. Daily weighing is a less expensive option than an implantable device and it carries no risk of complications. In order to gain approval from insurance companies and popularity with physicians, the makers of the implantable monitor will need to justify their costs.
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.