THURSDAY, April 19 (HealthDay News) -- Exercise reduced the risk of death in people with high blood pressure during the course of a new 12-year study.

The researchers also found that inactivity increased the risk of death during the study approximately the same amount as would an increase in blood pressure of 40 to 50 milligrams of mercury.

The 12-year study, which is slated for presentation April 19 at the World Congress of Cardiology, included more than 434,000 people in Taiwan. Of those participants, 54 percent were inactive, 22 percent had low activity levels and 24 percent had moderate or high activity levels.

The risk of death during the study period from all causes and, specifically, from cardiovascular disease -- conditions involving the heart and blood vessels, such as heart attack and stroke -- was much higher among those who were inactive compared to those who were active at all blood-pressure levels, including those with high blood pressure.

"The risk of developing [cardiovascular disease] has been proven to increase significantly as blood pressure increases," study author C.P. Wen, of the Institute of Population Health Science at Taiwan's National Health Research Institute, said in a World Heart Federation news release. "Reducing blood pressure to reduce cardiovascular disease risk is an important treatment goal for all physicians."

"This study is the first to quantify the impact of exercise on the risk profile of people with high blood pressure," Wen added. "Appreciating this relationship will hopefully help to motivate people with high blood pressure that are inactive to take exercise."

"To date, exercise and high blood pressure have been managed separately, with people mainly being concerned about their blood-pressure readings," Wen noted. "However, these results suggest that doctors should also discuss the importance of physical exercise as a means to manage the [cardiovascular disease] and all-cause mortality risk."

High blood pressure contributes to about half of all cases of cardiovascular disease, with disease risk doubling for every 10-point rise in diastolic blood pressure, according to the release. Diastolic blood pressure is the bottom number in a blood-pressure reading.

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The American Academy of Family Physicians has more about high blood pressure.