Practicing tai chi helps older people improve their balance and avoid falls, a review of studies has found. Tai chi is a form of Chinese martial arts now practiced as exercise. Researchers found 10 randomized trials analyzing the effect of tai chi on the incidence of falls or the time until an elderly person first has a fall. All studies compared tai chi to usual care or other treatments such as physical therapy, stretching or exercise. The analysis found that tai chi reduced the incidence of falls by 43 percent in those followed for less than a year and by 13 percent in those followed longer. There was no effect of tai chi on time to first fall, and there was some weak evidence that the practice reduced the number of falls that resulted in injury.

New test could detect Lyme disease sooner

Diagnosing if a tick bite caused Lyme or another disease can be difficult, but scientists are developing a new way to do it early — using a "signature" of molecules in patients' blood. Lyme typically starts as a fever, fatigue and flu-like symptoms — often but not always with a hallmark bull's-eye rash — and people usually recover quickly with prompt antibiotics. But untreated, Lyme causes more serious complications. Yet today's best available test often misses early Lyme. It measures infection-fighting antibodies the immune system produces. Those take a while to form, making the test more useful a month or more after infection sets in than when people first start feeling ill. The new approach essentially looks for a biochemical fingerprint that shows the body is beginning to respond to an infection, long before antibodies mobilize. It's based on cellular metabolism, subtle changes in the kind and amount of small molecules that cells produce, such as sugars and amino acids and fats.

Sleep problems tied to preterm births

Women with insomnia or other sleep problems have an increased risk of giving birth prematurely, a new study suggests. The observational study, in Obstetrics & Gynecology, included 2,172 women with a sleep disorder who gave birth between 2007 and 2012. They were matched with the same number of women with the identical ethnic, health and behavioral characteristics, but who did not have a sleep disorder. Overall, women with sleep disorders had a 14.6 percent prevalence of preterm birth (before 37 weeks of gestation), compared with 10.9 percent in those without a diagnosis. Those with insomnia had a 30 percent increased risk, and those with sleep apnea a 40 percent increased risk, compared with women without a sleep problem.

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