Oct. 31 (HealthDay News) -- Obese kids who develop hypertension may be watching far too much television, a new study suggests.

The finding "illustrates the need for considerable physician and family involvement to decrease TV time among obese children," study author Dr. Jeffrey B. Schwimmer, associate professor of pediatrics at University of California, San Diego, said in a prepared statement.

His team's study included 546 participants, ages 4 to 17, who were evaluated for obesity at clinics in California and Ohio from 2003 to 2005.

Information was collected on the amount of time the children spent watching TV, along with their body mass index (BMI) and blood pressure.

The researchers found that both the severity of obesity and the amount of time spent watching TV each day were significant independent predictors of hypertension.

Children who spent two to four hours a day watching TV were 2.5 times more likely to have hypertension than children who watched two or less hours of TV a day. Children who watched four or more hours of TV a day were 3.3 times more likely to have hypertension than those who watched less than two hours a day.

The findings are published in the December issue of the American Journal of Preventive Medicine.

"The American Academy of Pediatrics recommends that children watch less than two hours of TV per day but reports that only half (51 percent) of pediatricians make this recommendation to patients. TV viewing is an attractive target for intervention, particularly among obese children with hypertension. Several studies have demonstrated that changing TV time alone can lead to weight loss, without any changes in physical activity," said Schwimmer, director of weight and wellness at Rady Children's Hospital in San Diego.

However, in a commentary published in the same issue of the journal, Stuart J.H. Biddle, of the School of Sport and Exercise Sciences in Loughborough, U.K., noted that studies examining the link between TV viewing/sedentary behaviors and obesity can be difficult to interpret.

SOURCE: American Journal of Preventive Medicine, news release, Oct. 30, 2007