Washington, May 16 (IANS/RIA Novosti): A study released Wednesday at the annual meeting of the American Society of Hypertension in San Francisco found that talking on a mobile phone causes systolic blood pressure - the higher number in a blood pressure reading and the number doctors pay more attention to as a risk factor for cardiovascular disease - to rise significantly.

Researchers from the Guglielmo da Saliceto Hospital in Piacenza, Italy, took 12 blood pressure readings at one-minute intervals from 94 patients with mild hypertension. The patients’ mean age was 53.

Patients were seated in a comfortable armchair in a doctor’s consulting room and left alone after the first blood pressure reading was taken using an automatic device.

Researchers phoned the patients at least three times and found that when the patient was on the phone or receiving a call, their blood pressure reading jumped from 121/77 on average to 129/82.

The American Heart Association says less than 120/80 is a healthy reading for adults age 20 and older.

Data compiled by the US Census Bureau using the World Health Organization’s (WHO) Study on Global Aging and Adult Health show hypertension to be “by far one of the most common health conditions for those age 50 and older in Russia”, with nearly half of 50- to 69-year-olds and almost two-thirds of people over 70 suffering from hypertension.

Other data, gathered by Wireless Intelligence, an Atlanta-based mobile technology research and analysis firm, show that Russia is Europe’s largest mobile phone market by connections, or the number of active mobile devices that are connected to a network.

A report by Wireless Intelligence found that, as of June last year, there were 227.1 million mobile connections in Russia where the population is 141.9 million. That’s a mobile phone penetration of 160 percent.

In the US, where the Centers for Disease Control and Prevention (CDC) says around 30 percent of adults have high blood pressure, the ratio of mobile phone connections (321.7 million) to population (311.6 million) is 103 percent.

During the blood pressure study, neither diastolic blood pressure - the lower number in a blood pressure reading, which is a measure of the force of blood in the arteries when the heart relaxes between beats -- nor heart rate increased significantly when patients received a call.

Oddly, though, the researchers found that patients who got more than 30 calls a day seemed to have developed a form of immunity to the blood pressure spikes seen in the study. Beta-blockers also seemed to help stave off blood pressure spikes.

The researchers concluded that phone calls received when a mildly hypertensive patient is having a blood pressure reading could cause systolic pressure to spike, and advised that they turn off their phone, at least for the duration of the blood pressure test.