Wednesday, March 25, 2009

Loãng xương ở đàn ông

Bài này in bên Canada, nhưng chẳng hiểu sao có nhắc đến tôi. Công trình về ung thư tiền liệt tuyến (PC) và gãy xương thật ra công bố từ năm 2007, nhưng cho đến nay vẫn còn nhiều người nhắc đến. Có lẽ vì chuyện đàn ông ít ai nói, nên giới báo chí tìm cách khai thác.

Nói đến PC làm tôi nhớ đến hai bài trên New England Journal of Medicine cho thấy truy tìm PC chẳng có hiệu quả cứu sống bệnh nhân. Đây là 2 nghiên cứu khác, một lần nữa, cho thấy truy tầm ung thư ở đàn ông có thể gây tác hại hơn là giúp họ. Thế nhưng, kĩ nghệ truy tầm ung thư vẫn phát triển phây phây. Tôi sẽ quay lại chủ đề này trong một bài khác.

GL Andriole, et al. Mortality Results from a Randomized Prostate-Cancer Screening Trial. NEJM 2009; 360:1310-1319.

FH Schröder, et al. Screening and Prostate-Cancer Mortality in a Randomized European Study. NEJM 2009; 360:1320-8.


Update on Osteoporosis

Researchers are making some important discoveries about osteoporosis, including the fact that one in three men over 60 are affected by the disease.

The latest findings about this disease are looking at the connection between diet, over the counter heartburn drugs and how we are still not getting enough calcium in our diets.

Acid vs. Calcium

You might already know that you need plenty of calcium and vitamin D to keep your bones strong. But new research suggests there is another dietary move that is just as important. A diet heavy in carbs and low in fruits and veggies may lead to bone loss, according to a new study from Tufts University in Boston. It’s a matter of chemistry. When you digest carbs, the process turns your innards slightly acidic. And a high-acid environment leaches calcium from bones, says Tufts University researcher Bess Dawson-Hughes. In contrast, fruit and vegetables create a skeleton-friendly alkaline environment.In her study, Dawson-Hughes says an alkaline supplement lowered the amount of calcium that volunteers excreted by 20 percent. That supplement isn’t currently available outside the lab but, you can get the same benefit by tweaking your diet, she says.

Good Substutions

Include at least two vegetable or fruit servings at every meal and eat no more than two daily servings of carbs such as bread, cereal and pasta. To keep your bones even stronger, substitute acid-producing foods with more alkali-boosting foods. Substitute:

* Pasta for potatoes
* Fizzy drinks for fruit juices
* Meat and poultry for tofu
* Beer for wine
* Peanuts for raisins

Drug Update

Good news for osteoporosis sufferers locked into taking weekly or monthly pills: Aclasta is a new bisphosphonate that’s administered by once-a-year injections. It’s just as effective at preventing hip and spine fractures as other bisphosphonates. You should consult with your doctor before taking this drug and be aware of the Health Canada advisory regarding this new drug.

Heartburn Medication Alert

Medications used for heartburn, such as Losec and Nexium, can be a problem if taken long term. In a University of Pennsylvania study, patients who used these for more than a year had a 44 percent higher risk of hip fracture. Dr Yu-Xiao Yang, author of the study, says the drugs may interfere with the absorption of dietary calcium and vitamin B12, both of which are needed to stop bone loss.

“It’s important to carefully weigh the risks and benefits. If a patient is truly benefiting from the drug, they should use the lowest effective dose,” he says. “And ensure they’re getting adequate calcium and vitamins.”

Connection to Prostate Cancer

One in three men over 60 are affected by osteoporosis and, if they suffer a hip fracture, they are more likely than a woman to die because of it.

Now, research from Sydney’s Garvan Institute shows that men who develop prostate cancer face a 50 percent higher risk of fracture, which increases to nearly a doubled risk if they are receiving androgen deprivation therapy (ADT). Interestingly, most of the men who developed prostate cancer started out with a higher-than-average bone mineral density (BMD).

“Obviously the higher BMD did not protect them against fracture,” says Associate Professor Tuan Nguyen, who led the study. “Men with prostate cancer should be checked for osteoporosis, particularly if they are being treated with ADT.

Online Calculators

Getting enough calcium is the key to preventing fractures, but how do we know we’re getting enough? To find out if your diet’s lacking, try the Calcium Calculator from Informed Health Online.

Over 60 and want to find out your risk of suffering a fracture in coming years? Check out the Garvan Institute’s new Fracture Risk Calculator.

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