London, Feb 26 (IANS): Parents must watch out as kids, who spend more than two hours watching television, computers or video consoles in a day run a 30 percent greater risk of developing high blood pressure, says new research.

Doing no daily physical activity or an activity which is less than an hour a day makes one more prone to risk by 50 percent, said researchers from University of Sao Paulo, in Brazil.

"The study shows the number of new high blood pressure cases and the connection between physical activity and different sedentary behaviours with the risk of high blood pressure in European children," explained lead researcher Augusto Cesar de Moraes from the University of Sao Paulo.

The scientists based their conclusion on data gathered over two years from eight European countries (Spain, Germany, Hungary, Italy, Cyprus, Estonia, Sweden and Belgium). It involved 5,221 children, who were between two and 10 years old at the beginning of the study.

The cumulative incidence of high blood pressure in this population during the two years analysed is high: 110 in 1,000, the findings showed.

"The figures are worrying, given that sedentary behaviours are common in infancy and subsequently, later in life," said the authors.

The researchers observed that not doing an hour of physical activity a day increases the risk of high blood pressure by 50 percent.

"Scientific evidence indicates that physical activity is a powerful vasodilator. Therefore, the rate of oxygenation of the heart increases, and at the same time, decreases arterial pressure," the researchers concluded.

The study was published in the International Journal of Cardiology.