Vitamin C supplements tied to men's kidney stones

NEW YORK - Men who take vitamin C supplements are at higher-than-average risk of developing kidney stones, a new study from Sweden suggests.

The findings don't prove the vitamin itself triggers stones to form. But researchers said that because there are no clear benefits tied to taking high-dose vitamin C, people who have had stones in the past might want to think before taking extra supplements.

"I don't think I would hold this up and say, ‘You shouldn't take vitamin C, and here's the evidence,'" said Dr. Brian Matlaga, a urologist who studies kidney stones at Johns Hopkins Medicine in Baltimore.

But, "When you talk to patients, a lot of times you'll find patients are taking non-prescribed medications, like vitamin supplements… and there may not be great evidence that there's an actual health benefit associated with these," he told Reuters Health.

The new finding "suggests that stone formers who take regular vitamin C may actually place themselves at increased risk," said Matlaga, who wasn't involved in the study.

Researchers led by Laura Thomas of the Karolinska Institutet in Stockholm used data from a large study of middle-aged and elderly Swedish men who answered a series of questions on their diet and lifestyle, then were tracked for an average of 11 years.

The current analysis included 907 of those men who said they took regular vitamin C tablets and more than 22,000 who didn't use any nutritional supplements.

Of the vitamin C users, 3.4% developed kidney stones for the first time during the study, compared to 1.8% of non-supplement users. Men who took vitamin C supplements at least once a day had the highest risk of kidney stones, researchers reported Monday in JAMA Internal Medicine.

"It has long been suspected that high doses of vitamin C may increase the risk of kidney stones as some of the vitamin C absorbed by the body is excreted in urine as oxalate - one of the key components of kidney stones," Thomas told Reuters Health by email.

Stones are made up of tiny crystals, which can be formed by calcium combining with oxalate. They usually pass on their own, but can cause severe pain in the process. Larger stones occasionally require surgery.

Men are more likely to form stones than women.

‘An important part of a healthy diet'

The findings don't mean people shouldn't get plenty of vitamin C through fruits and vegetables, researchers said. The antioxidant is important for bone and muscle health - and severe deficiency can cause scurvy.

"Vitamin C is an important part of a healthy diet," Thomas said. "Any effect of vitamin C on kidney stone risk is likely to depend both on the dose and on the combination of nutrients with which it is ingested."

Swedish supplements, like those the study participants would have taken, typically contain about 1,000 milligrams (mg) of vitamin C per tablet, she noted. Most vitamin C supplements sold in the US contain either 500 or 1,000 mg.

The US Institute of Medicine recommends 90 mg per day for men - the amount in a small glass of orange juice or a cup of broccoli - and 75 mg for most women.

Matlaga said more research is needed to determine for certain whether reasonable doses of vitamin C may increase the risk of kidney stones. For now, he said people who haven't had kidney stones before shouldn't worry about any related risks tied to the vitamin.

source: abs-cbnnews.com

Robotic surgeries costlier but safer - study

Patients who have robot-assisted surgeries on their kidneys or prostate have shorter hospital stays and a lower risk of having a blood transfusion or dying -- but the bill is significantly higher, a study found.

The analysis, which appeared in the Journal of Urology, compared increasingly common robotic surgery with two other techniques for the same surgery and found that direct costs can be up to several thousand dollars higher for the robotic type.

Touted as less invasive and more efficient, robotic surgeries typically use a laparoscopic or "keyhold surgery" approach, in which tools and a tiny video camera are inserted into the body through one or two small incisions.

Robotic surgery replaces a surgeon's hands with ultra-precise tools at the ends of mechanical arms, all operated by the surgeon from a console.

"I think the take home message is that robotic (surgery), looking at our study, had certain beneficial outcomes compared to open and laparoscopic procedures," said study leader Jim Hu at Brigham and Women's Hospital in Boston.

Hu and his team analyzed surgery data from a national government database to see if the costlier robotic surgeries were cost effective with extra benefits over older techniques.

During the last three months of 2008 -- the most recent data available that allowed a comparison among robotic, open and laparoscopic surgeries -- more than half of all prostate removals involved robot-assisted surgery.

About three percent of prostate patients had standard laparoscopic surgery and 44 percent had open surgery. Open and laparoscopic surgeries were still more common than robotic surgeries for kidney repairs and removals.

Among patients who had their prostate removed, none died from laparoscopic or robotic surgery, whereas two out of every 1,000 died after the open procedure.

About five percent of the men who had open surgery needed a blood transfusion, compared to less than two percent of men who had robot-assisted surgery. The open-surgery group also stayed in the hospital about one day longer than the robotic group.

The results were similar for people who had kidneys removed.

The trade-off was the cost, with robotic prostate removal costing about $10,000 on average, roughly $700 more than laparoscopic surgery and $1,100 more than open surgery.

For kidney removal, robotic surgery cost $13,900, which was $2,700 more than laparoscopic and $1,300 more than open surgery.

David Penson, a surgeon at Vanderbilt University Medical Center who was not part of the study, said more consideration should have been given to the state of patients afterwards. Emphasis should be lmited on procedure, he said, as opposed to surgical skill.

"Years ago, this was thought to be the be-all-end-all operation, particularly with prostate surgery. We were going to get patients out of the hospital quicker, have better potency and incontinence outcomes," he told Reuters Health.
"And the reality of it is that... there are some benefits -- but not as much as we had hoped."

source: interaksyon.com