As we were putting together this year's top 10 list, uncertainty became a motif. Here at the beginning of the flu season, we don't really know if the H1N1 flu pandemic will stay controlled by public health measures, or take off in some unexpected way. Even when a large randomized clinical trial seems to have settled an important matter, it's hard to say how the findings will be applied exactly. No panic about this pandemic After the first several weeks of uncertainty, most of the news about the 2009 H1N1 “swine flu” pandemic has been reassuring. Much of that has to do with the nature of the H1N1 virus itself, which spreads easily and makes people sick, but so far rarely in a life-threatening way. And the word pandemic is misunderstood: a disease is considered pandemic if it has spread globally and affects a larger-than-usual proportion of the population. The disease needn't be severe. But a major reason for the calm has been the measured public health response. Plenty of information has been made available (this is the first Internet-age pandemic). A vaccine was developed and put into production, although shortages are a serious concern. Health officials gave us simple, concrete things to do to protect ourselves and others: cough and sneeze into your sleeve, wash your hands often, get vaccinated with both the seasonal and H1N1 flu vaccines, stay home if you're feeling sick. This wasn't the flu pandemic that the experts were expecting. For years, they've eyed the H5N1 bird flu virus circulating in Asia to see if it would mutate and become transmissible among humans. Instead, H1N1 emerged in Mexico with a complicated quadruple pedigree: two strains of swine flu, a human strain, and a bird one. Hospitalization and death rates from the new virus have been high in healthy young adults and quite low in people older than 60. Bad fat, good fat The visceral fat — the fat located in our abdomen — churns out inflammatory factors and hormones. By comparison, the subcutaneous fat, which lies under the skin, is metabolically sedate. Findings published in 2009 further implicate visceral fat as a source of health woe, while largely exonerating the subcutaneous deposits. For example, Framingham Heart Study researchers reported that visceral, not subcutaneous, fat was associated with calcium deposits, a marker for atherosclerosis, in the body's main artery, the aorta. White fat cells store fat, and most of the fat in our bodies — visceral and subcutaneous — is white fat. But there are also brown fat cells that actually burn fat. We have brown fat as newborns to help with the regulation of body heat, but it's long been believed that it soon disappears. A surprising trio of articles published in The New England Journal of Medicine used PET scans to show that we actually retain appreciable amounts of brown fat as adults in an area between the shoulder blades, and that the more brown fat an adult has, the more likely he or she is to be lean with healthy metabolic indicators. Researchers are now studying how brown fat cells can be increased or activated. The visceral fat findings are shifting attention to waist size as a measure of obesity, although it's not so simple: subcutaneous fat also contributes to waist size, especially in women. Still, the notion that diet and other habits should be judged by their effect on waist circumference is gaining traction. An alternative to warfarin? Millions of people depend on warfarin (Coumadin), especially those with atrial fibrillation, a common heart rhythm disorder. By blocking vitamin K, the drug reduces the risk for blood clots and, in turn, for stroke and other life-threatening, clot-related disorders. But warfarin interacts with dozens of drugs, herbs, and foods. Frequent blood tests are often necessary to make sure the blood's clotting capacity is in a safe range. Patients and their doctors have accepted these drawbacks for lack of a good alternative. But in 2009, one might have been found. Dabigatran, which is already approved in Europe for limited purposes, acts directly on thrombin, one of the key players in the formation of blood clots. No blood monitoring is needed, and because of the way the drug is metabolized, there are far fewer interactions to worry about. Results show that dabigatran matches up well against warfarin. At the smaller dose, it was just as effective at preventing strokes and caused fewer major bleeds. At the larger dose, it was more effective than warfarin at stroke prevention and caused a similar number of bleeds. The news wasn't all good: heart attacks and gastrointestinal side effects were more common among those taking dabigatran than those taking warfarin. These micros are major Messenger RNA reads the DNA of our genes and uses that code to assemble proteins, the building blocks of all forms of life. Already microRNAs are playing an important role in helping cancer doctors make more accurate diagnoses and prognoses and choose more effective treatments. For example, in 2009, researchers reported that liver cancer patients whose tumors had lower levels of a particular microRNA, called miR-26, had a much worse prognosis, but also a better response to one kind of treatment. Promising results for macular degeneration and respiratory syncytial virus infection have been reported in humans, and successful treatments using microRNAs have been achieved in mice. Compared to drugs, microRNAs are easy and cheap to manufacture. And researchers have high hopes that microRNA medicine will yield pinpoint control, so only diseased cells would be affected. Seeking the sweet spot High blood sugar levels aren't just a problem for people with diabetes. Elevated blood sugar is associated with worse outcomes for heart attack and stroke patients and, in fact, for hospital patients of all kinds. Results from a large randomized trial (too cutely called the NICE-SUGAR trial) showed that the death rate for tightly controlled patients was higher than it was for patients controlled to more conventional levels. The difference was 2.6 percentage points (27.5% vs. 24.9%), which may not seem like much but translates into many deaths given the number of ICU patients. Study results featured in our top 10 list for 2008 suggested people with diabetes might be harmed, not helped, by overly ambitious goals for blood sugar control (an HbA1c goal of below 6%). Overdoing blood sugar control in the ICU might be harmful for several reasons. Low targets result in more episodes of extremely low blood sugar, or hypoglycemia, which can trigger a cascade of events with mortal consequences. The insulin used to achieve low blood sugar may have negative effects. Blood sugar control doesn't make the sugar disappear; it goes into cells. That surge of sugar may disrupt normal cell functions that wind up affecting the heart and other vital organs. CRP: Ready to enter? Late in 2008, results from the industry-funded JUPITER trial showed that people with normal LDL cholesterol levels (less than 130 mg/dL) but relatively high CRP levels (2 mg/L or higher) could cut their risk of having a heart attack or stroke in half by taking a high dose (20 mg) of a powerful statin drug, rosuvastatin (Crestor). CRP stands for C-reactive protein, a chemical in the blood that's a good indicator of inflammation. Statin drugs are taken primarily to lower LDL levels, but this was added proof that they also calm inflammation. Screens with holes Fresh doubts emerged about the wisdom of the current screening tests for breast and prostate cancers. A provocative analysis in The Journal of the American Medical Association (JAMA) came to the conclusion that the past 20 years of screening mammography for breast cancer and prostate-specific antigen (PSA) testing for prostate cancer has led to detection and treatment of many cancers that pose minimal risk while achieving only modest reductions in the number of more advanced cases. Earlier in the year, results from two large studies of PSA screening were equivocal. Do your friends make you fat? We know, we know: we gain weight because we don't eat the right foods and don't exercise enough to burn off the calories. But a new wave of research is showing that the causation of weight gain and a variety of other health-related behaviors has a social dimension, spreading through social networks as if they were contagious. Social networks are the vast web. - Agencies Source: Harvard Health Publications, Harvard Medical School __
