News April 2006 Issue

In the News: 04/06

Long-Term Warfarin Use Increases Fracture Risk

Warfarin, a commonly prescribed anti-coagulant for patients suffering from atrial fibrillation, may contribute to fracture risk in men. A study of 13,881 Medicare patients included 4,461 patients classified as long-term users of warfarin (more than one year), 1,833 patients classified as short-term users (90-364 days), and 7,587 patients who did not take warfarin. The average age of all patients was 79 years. Although those who used the drug for less than a year showed no association with fracture risk, long-term use of warfarin was associated with a 25 percent increase in fracture risk in men. The increased risk was not seen in women or in those who took the drug for less than a year.

Warfarin prevents coagulation by inhibiting vitamin-K, which activates clotting factors. However, vitamin K is necessary to activate osteocalcin and other bone-matrix proteins to maintain bone strength. The study’s conclusion: Inhibiting vitamin K may increase the risk of osteoporotic fractures. Researchers suggested that elderly patients on long-term warfarin should protect themselves from osteoporosis by exercising, getting enough calcium and vitamin D, and by quitting smoking.

Although patients on warfarin have traditionally been instructed to avoid vitamin-K-rich foods, researchers now suggest that a moderate amount of vitamin K should be consumed through sources such as green vegetables, dairy products, fish, liver, and eggs.

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Healthy Nerve Fibers May Be Source Of Chronic Pain

Despite previous research that has focused on illness- or injury-damaged nerve fibers as the source of chronic pain, a recent study has found that healthy, undamaged nerve fibers may be to blame.

According to a recent report in the Journal of Neuroscience, British researchers have identified nerve cells called nociceptors (damage detectors) that, when activated by disease or injury, send electrical pain-indicating impulses to the brain. The faster these damage-detecting nociceptors send their impulses, the stronger the ongoing pain. The rate at which nociceptors send their impulses, say researchers, may be heightened by inflammation caused by degeneration of the injured nerve fibers within the same nerve. 

Although no one knows what causes undamaged nerve fibers to continually send pain impulses to the brain, researchers agree that further examination should help in the search for new analgesics to treat ongoing pain.

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Old Test Seen As New Hope For Back Pain

The electromyogram (EMG), a test that has for more than 60 years been used to detect a muscle’s abnormal electrical activity to diagnose a variety of conditions, is showing new life as an indicator of spinal stenosis. This, say researchers at the University of Michigan Health System, should now provide a more definitive diagnosis for spinal stenosis, reducing not only the misdiagnoses of other neuromuscular conditions that exhibit similar symptoms, but even the need for surgery.

The study examined 150 patients (ages 55-80) with back pain who underwent both MRI (magnetic resonance imaging) and EMG testing. EMG results showed a substantial difference between the spinal stenosis patients and those suffering from common neuromuscular back pain. Researchers attributed this to the fact that EMG, unlike MRI, provides more than a picture of a nerve—it is able to test nerve function and reveal actual nerve damage. The symptoms of spinal stenosis, said researchers, are shared by many other diseases, including arthritis, and this can lead to costly misdiagnoses and unnecessary back surgery.

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More Magnesium Builds Stronger Bones

New research confirms that magnesium benefits bone health. A study reported in a recent issue of the Journal of the American Geriatrics Society examined the magnesium intake of 2,038 men and women in their 70s and compared it to their bone densities. Higher magnesium intake (from either diet or supplements) was associated with greater bone strength in both men and women (bone density increased by approximately 2 percent for every 100mg increase in daily magnesium intake). Researchers suggest magnesium may increase bone density by elevating bone-building hormones or substituting for calcium. Good dietary sources of magnesium include beans, whole grains, wheat germ, nuts, seeds, avocados, and kale.