Air pollution joins fatty food and second-hand smoke as a heart risk
AIR pollution could be just as damaging to the heart as fatty foods and second-hand smoke. A study published online this week in CirculationResearch shows that vehicle exhaust can trigger plaque build-up in the arteries that can lead to heart attack and stroke. The study found that it’s the tiniest pollutant particles, known as nanoparticles, that are the most toxic. Nanoparticles are about one-thousandth the width of a human hair, and are also the most abundant particles found in city air. Over a five-week period, scientists exposed mice with high cholesterol to one of two sizes of air pollutant particles from Los Angeles freeway emissions. They were then compared to mice that received filtered air containing very few particles. Mice exposed to nanoparticles had 55 per cent more plaque development in their arteries than those breathing filtered air, and 25 per cent more plaque development than mice exposed to slightly larger fine-sized particles. Air quality regulations need to be more strict, say the authors, to better control nanoparticle levels. CircRes 2008;doi:10.1161/circresaha.107.164970 (Araujo JA, et al) CANCER treatments are becoming more effective at battling the disease, but they can still have a number of side effects, including severe tiredness. Now new research has found that drugs commonly used to treat anaemia and attention deficit disorder can help cancer patients to overcome fatigue. In the latest issue of the Cochrane Database of Systematic Reviews, researchers report that two drugs used to increase the number of red blood cells in the body — erythropoietin and darbepoietin — are also effective in relieving fatigue in cancer patients with anaemia. They also found that the stimulant called methylphenidate (Ritalin) can improve cancer-related fatigue. The conclusions are based on 27 separate studies in which a total of 6746 participants were randomly assigned to take one of the drugs or a placebo. Despite the effectiveness of drug treatments for fatigue, the authors claim that exercise and counselling may also help. Cochrane Database Syst Rev 2008;1 (Minton O, et al) ALTERING the immune system of patients with heart failure reduces their risk of hospitalisation and death, concludes a new study in The Lancet . Scientists used a new method called ‘‘ immune modulation therapy’’ (IMT), in which a small sample of blood is taken from a patient, intentionally damaged by exposure to oxygen, ozone and ultraviolet light, and then injected back into the same patient. The damaged blood tricks the immune system into producing large numbers of antiinflammatory cells, which help to heal the heart. The trial involved 2246 patients with heart failure. Half were given IMT once a month for six months, and the other half had blood taken, but were given back a salt solution instead of their damaged blood. In patients with no history of heart attack, IMT reduced the risk of rehospitalisation and death by 26 per cent. In those with the most severe heart failure, those risks were reduced by 39 per cent. Lancet 2008;371:228-236 (Torre-Amione G, et al) MUSCULAR dystrophy — an inherited disease that causes progressive muscle weakness — could one day be treated using stem cells generated from a patient’s skin. In the current issue of Nature Medicine , scientists have shown that transplantation of mouse stem cells directly into the muscles of mice with muscular dystrophy can lead to the growth of new, healthy muscle cells. The technique, which identifies and uses only those stem cells that are destined to become muscle cells, was found to improve overall muscle strength and co-ordination in treated mice. Carefully selected stem cells were injected into the leg muscles of mice lacking the dystrophin protein — the same protein missing in patients with Duchenne muscular dystrophy. Three months later, treated mice had stronger muscles and better co-ordination than untreated mice, although they were not quite as strong or coordinated as normal mice. NatMed 2008;doi:10.1038/nm1705 (Darabi R, et al) PEOPLE with chronic fatigue syndrome (CFS) suffer from extreme physical and mental exhaustion, but the cause of the disease is unknown and there is no cure. Now a new study in the JournalofClinicalEndocrinology and Metabolism has found that low morning levels of a hormone called cortisol may be linked to CFS in women. The findings suggest that increasing cortisol levels may be a potential treatment for CFS. Researchers screened 19,381 residents of the US state of Georgia by telephone interview and identified 292 people with CFS and 163 healthy controls. Of these, 75 people with CFS and 110 controls collected their own saliva on one normal workday, immediately upon waking and 30 minutes and 60 minutes after waking. Compared to healthy women, women with CFS had significantly lower cortisol levels. There was no difference in cortisol levels between men with CFS and healthy men. JClinEndocrinolMetab 2008;doi:10.1210/jc.2007-1747 (Nater UM, et al) SEEING a chiropractor doesn’t increase the risk of stroke, concludes a study in the latest issue of Spine . In fact, the risk is the same whether you visit a chiropractor or the family GP, and that risk is very low. Previous studies have suggested that the neck manipulation done by chiropractors can increase the risk of suffering a vertebrobasilar artery (VBA) stroke. In this type of stroke, an artery supplying blood to the brain is torn, and a clot dislodges and travels to the brain, blocking circulation. Researchers examined medical records from hospitals in Ontario, Canada, over a nine-year period. Only 818 people suffered a VBA stroke during this time. While these people were more likely to have visited a chiropractor than those who did not go on to have as stroke, they were also more likely to have visited the family doctor. Researchers say the association is due to patients seeking help for neck pain — an early sign of stroke — rather than these services causing the stroke. Spine 2008;33:S176-S183 (Cassidy JD, et al) Want to know more? Items are referenced where possible. A reference such as ‘‘ 2007;35:18-25’’ means the source article was published on pages 18-25 in volume number 35 of the publication, in 2007. A doi number or website address is used for research published on a journal’s website.
Vehicle emissions: Clog the arteries