New studies underscore risks of high CT scan radiation

Two new studies add to the growing awareness that the high radiation doses from computed tomography (CT) scans can be harmful.

About 70 million CT scans were done in the United States in 2007, up from 3 million in 1980, medical records show. Using such records, researchers from the University of California, San Francisco estimate that one in 270 women and one in 600 men who undergo CT angiography (a heart scan) at age 40 will develop cancer as a result. For head CT scans, the estimated cancer toll is one in 8,100 women and 11,080 men.

A second study, by National Cancer Institute researchers, estimates that 29,000 future U.S. cancers could be related to CT scans done in 2007.

Both studies appear in the current issue of Archives of Internal Medicine. An accompanying editorial by UCSF researcher Rita Redberg urges doctors to "carefully assess" the benefits of each CT scan, and "fully inform" patients of the radiation risks.

- Marie McCullough

Assessing your health? Your spouse may know best

For married people worried about their health, a good source for an assessment could be their spouse, according to a study in the current issue of the Archives of Internal Medicine.

Researchers from Bar-Ilan University in Israel and the University of California, San Francisco compared health assessments by 673 people and their spouses from 2000 through 2006 with death records.

The researchers found that spouse-rated health status was at least as strong a predictor of death as self-assessments. Taken together, the health assessments were particularly accurate, the study found.

The researchers questioned whether a spouse might be more aware of biologic and physiological issues that others would miss.

Regardless of the reasons, the researchers concluded that spouse and self-rated health status together were better than someone's self- assessment alone.

- Josh Goldstein

Small study shows TV locks could help in weight loss

Breathalyzer-linked ignition locks stop drinkers from driving when they've had too much. Could time-triggered television locks stop overweight and obese people from watching when they've watched enough? More important, would they lose weight?

A small new study suggests yes and yes.

Researchers recruited 36 adults who normally watch an average of 41/2 hours of TV a day and had body mass indexes between 25 (overweight) and 50 (very obese). After an observation period, they were randomly divided into two groups for three weeks.

Recruits in one group did their usual thing. Members of the other group faced password- and key-protected locks that shut the tube off after 50 percent of their normal weekly viewing time had elapsed. Electronic monitors tracked physical activity.

The result, published in the current Archives of Internal Medicine: People in the locked-TV group expended an average 119 more calories a day than they had before, a significant change. Interestingly, there was no meaningful drop in caloric intake; the authors note that studies of children have found changes of a similar degree but on the intake side, not output.

- Don Sapatkin

Doctors must be aware of teens' dangerous 'choking game'

Health officials are beginning to pay more attention to a potentially dangerous activity among adolescents called "the choking game."

Participants try to initiate a euphoric feeling by cutting off air flow to the lungs - partially strangling themselves with ties or belts, for instance - and depriving the brain of oxygen.

Researchers say the activity can lead to headaches, fractures, seizures, and brain injury. It can also be fatal if the person is alone, passes out, and can't release the ligature.

But many physicians don't know about the game or are unable to identify the warning signs, according to a report published recently in the online edition of the journal Pediatrics.

In a survey of 163 pediatricians, nearly a third had not heard of the game. Of those who had, a quarter of them could not identify the warning signs, which include bruising around the neck, bloodshot eyes, and ligatures tied in strange knots or found in unusual places.

- Sandy Bauers