| ||What Your Doctor Is Reading || |
Update From the Medical Journals: May 2010
May 31, 2010
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.
Vitamin E May Lessen Harm from Fatty Liver
On April 29, the New England Journal of Medicine published a study showing that vitamin E may limit the liver damage that occurs in "fatty liver." Obesity can cause fatty liver. Fatty liver also goes by the names "non-alcoholic steatotic hepatitis" (NASH) and "non-alcoholic fatty liver disease" (NAFLD).
This liver disease occurs when your body has an unhealthy metabolism. It is particularly common in people who have diabetes. When the liver is overloaded with fats, the fats can harm the liver. Fatty liver occurs in about 9% of Americans. Some experts estimate that up to 20% of Americans have unhealthy fat deposits in the liver. A few of these people have severe liver damage or even liver failure from fatty liver. Before now, managing your weight has been the only known treatment for fatty liver.
Researchers decided to study vitamin E as a treatment for this condition. Vitamin E is an antioxidant and has the potential to neutralize certain byproducts of our metabolism. Reactions to those byproducts could otherwise be toxic to cells. The researchers also studied a medication called pioglitazone (Actos). This drug improves insulin resistance, a metabolic change that is common in fatty liver.
Researchers randomly divided 247 adults with NASH into three groups. One group took 800 IU of vitamin E daily, one group took pioglitazone, and one group got placebo pills. Before treatment and after nearly two years of treatment, liver biopsies were done to check for fat, inflammation and cell damage. NASH is a disease that can change along with your metabolism, so it was not surprising that 19% of the group treated with placebo had significantly less inflammation and less fat at the end of the study than at the start of the study.
It was impressive to see that 43% of the people in the vitamin E group improved. The pioglitazone was only slightly more helpful to the liver inflammation than the placebo pills, and many members of this group gained weight from the drug. After stopping the treatment with vitamin E, liver inflammation seemed to come back quickly based on blood tests.
The study did not include people with diabetes, and it did not continue long enough to check for serious side effects from treatment with vitamin E. Vitamin E at this high dose can increase a person's risk for bleeding. Although questions remain about whether the benefit of long-term treatment is greater than the risk, it seems sensible for vitamin E to be recommended for people who have worse-than-average liver injury from NASH.
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Sweet Drinks May Increase Blood Pressure
A study published May 24 in Circulation: Journal of the American Heart Association looked at drinks sweetened with sugar or high-fructose corn syrup. These included sodas, lemonade and sweetened fruit drinks or fruit punch. Beverages sweetened by artificial (zero-calorie) sweeteners did not have any impact on blood pressure. But other sweet beverages did.
Researchers surveyed 810 adults who had either mild-to-moderate hypertension or prehypertension. (Prehypertension is blood pressure higher than 120/80, but less than 140/90 without medicines.) The researchers encouraged everyone in the study to pay attention to their weight, exercise more and eat a healthy diet. People also received counseling on ways they could make these changes. Before the study, participants drank, on average, slightly less than one serving of sweetened beverages a day. After 18 months, the researchers again looked at the amount of sugar-sweetened beverages people drank. The group had reduced their beverage intake by about half, had lost weight and improved their blood pressure.
People who drank one less sugar-sweetened drink per day, had an average drop of 1.8 millimeters of mercury (mm Hg) in systolic blood pressure and a 1.1 mm Hg average decrease in diastolic blood pressure. This may not sound like much, but even small changes in blood pressure can make a difference in your health. When weight loss differences were accounted for, there was still a measurable drop in blood pressure in people who cut their sweetened drinks. Research has previously estimated that a long-term 3 mm Hg decrease in systolic blood pressure can lower deaths from stroke by 8% and deaths from heart disease by 5%.
According to the American Heart Association, soft drinks account for 33% of added sugar intake for Americans. Added sugar in our daily diet has already been found to contribute to obesity, risk for diabetes and unhealthy cholesterol levels. (Added sugars in our diet lower HDL, the "good" cholesterol, and raise triglycerides in men and women. They also increase LDL in women.) Sugar has also been linked to fatty liver and abdominal obesity. To stay hydrated, particularly when you exercise, choose drinks that are not sweetened with sugars or corn-syrup.
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More News in Brief
- Eating Nuts Seems to Help Cholesterol. The Archives of Internal Medicine reported on May 10 that eating nuts appears to be linked to better cholesterol levels. This confirmed earlier studies that suggested a health benefit from nuts. Researchers combined data from 25 smaller studies and analyzed them to uncover any patterns between eating various amounts of nuts and cholesterol levels. People who ate 2.4 ounces of nuts each day, on average, had a 7.4% lower LDL level and 5% lower total cholesterol, compared with people who didn't eat nuts. The 583 people in this study were not on medicines for lowering cholesterol. No one in this analysis had "extreme" nut-eating habits, so we don't know if eating more nuts would add any additional benefits. We don't have research that shows this. My suggestion would be to make a point to regularly include nuts in your diet if you have high cholesterol, but avoid "going nuts" about nuts.
- Lifestyle Habits Could Take Years Off Your Life. A simple study that was included in the April 26 Archives of Internal Medicine is another reminder of the power of good and bad lifestyle habits. The study followed 4,886 adults in Britain ages 18 and older for 20 years and recorded deaths. At the beginning of the study, people completed a one-time survey about their lifestyle habits. The researchers focused on four bad habits: smoking, heavy drinking (more than three alcoholic drinks per day for men and more than two for women), exercising less than two hours per week, and eating fruits and vegetables fewer than three times daily. The researchers assumed that these habits persisted until the end of the study. After 20 years, the researchers looked to see whether certain habits were associated with a higher likelihood of early death. Almost all of the subjects were young enough that deaths during the study period would be considered premature. Among the 314 people who had all of the four bad habits, 91 died (29%). Among the 387 people who had none of these bad habits, 8% died. The authors concluded that these four bad habits combined had the same effect on a person's risk for dying that being 12 years older would have.
- New Treatment Improves Diabetic Eye Disease. Diabetes can cause blindness by damaging the retina. This is called retinopathy. The most severe cases of diabetic retinopathy involve a critical part of the retina called the macula. The macula is the part of your eye that sees what is straight ahead of you; it normally gives you your clearest vision. Swelling of the macula in severe cases of retinopathy is called macular edema. Researchers reported a huge advance in treatment for macular edema. The report was published April 27 in the journal Ophthalmology. Laser treatment is already used to treat diabetic macular edema. Laser treatment combined with injections of a new medication was much more effective. The new medication is a manufactured antibody called ranibizumab. The drug works by blocking a natural stimulant (growth factor) that affects blood vessel growth. The study included almost 700 people, and some people had both eyes treated. Half of the eyes that were treated with ranibizumab and laser had meaningful improvement in vision. Only about 30% of eyes that got laser treatment alone improved.
- Beta Blocker Drugs Might Help COPD. A report published in the May 24 issue of the Archives of Internal Medicine showed that a family of medicines called beta blockers may improve survival and reduce flares in people with chronic pulmonary disease (COPD). COPD is the name for lung disease in people who have either emphysema, chronic bronchitis or both. This surprised researchers because traditionally, doctors have avoided giving beta blockers to people with COPD, due to worries that the medicine would trigger airway narrowing and wheezing. Some beta blocker medicines are metoprolol (Toprol XL), carvedilol (Coreg) and atenolol. These drugs are known to reduce heart attack risk, improve survival in chronic congestive heart failure, and regulate heart rate in people who have heart disease. The study was based on information researchers got from the medical charts of 2,230 patients with COPD. They followed these people for an average of about seven years. About one third of the patients took beta blocker medicines. During the study years, 27% of people who used a beta blocker died compared with 32% of people with COPD who did not take a beta blocker medicine. Among the people who took a beta blocker, 43% had at least one flare-up of COPD, while 49% of people who didn't take a beta block had a flare-up. It is going to be difficult to tease out the results of this study. Those people who were not on beta blockers might have had a more active pattern of lung disease, causing their doctors to purposefully avoid the drugs. Although firm conclusions can't be drawn from this study, it is likely that it will lead to additional research in this area. It may also help doctors feel more comfortable prescribing beta blockers to people with COPD who have a reason besides lung disease to take these drugs.
- FDA Approves Novel Treatment for Prostate Cancer. On April 29, the U.S. Food and Drug Administration approved a new treatment for prostate cancer. This was a notable event because it is a cancer vaccine and the first of its kind to be formally approved for use. It is not a vaccine to help prevent prostate cancer. It is only given after the cancer is diagnosed. The vaccine must be customized for each patient. White blood cells are collected and "trained" by being exposed to cancer proteins in a laboratory. When they are re-injected into the patient, the cells may be more likely to recognize and fight prostate cancer cells. It is considered a vaccine because it boosts the immune system. Some people have said the vaccine should be called a "theracine" because it is used for therapy, not for prevention.
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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.