When we're asleep, our pulse and blood pressure usally rest as well. However, the normal heart rate 'dip' during sleep may be lessened in some people, and these persons have an increased overall mortality rate. In the case of blood pressure, spike-like increases may sometimes occur at night, which can be linked to the occurrence of high blood pressure (hypertension).

A year ago a European study found that the rsik of hypertension was increased with long-term noise exposure. The results were basedon almost 5,000 people living near one of 6 major european airports.

Now Greek researchers and colleagues elsewhere in Europe studied 140 volunteers living near Athens, Malpensa (Italy), Arlanda (Sweden), and Heathrow (UK) airports; they reported their findings in the European Heart Journal. The participants wore blood presure monitors that checked the blood pressure every 15 minutes throughout the night. Noise levels were recorded if the decibels exceeded 35. A recorder allowed the source or type of the noise to be identified later.

Systolic blood pressure increased an average of 6.2 mmHg and diastolic an average of 7.4 mmHg within 15 minutes of an 'aircraft event' as well as when other noises reached a critical level. The noises didn't actually wake the subjects, so the blood pressure changes weree at the subconscious level.

This news encourages me to support those who want to limit night-time take-offs and landings still further. Even if noise (including subconscious noise) is only a minor factor, one should try to reduce all those stressors that can cause hypertension.