HARTMANN in South Africa
Monitoring > Research and Science > Falling temperatures may cause a rise in blood pressure

Falling temperatures may cause a rise in blood pressure

29 January 2009 – A French study has found a strong correlation between blood pressure and outdoor temperature in people over 65. As a result, the investigators advise that, during periods of extreme temperatures careful monitoring of blood pressure and appropriate treatment could contribute to reducing the consequences of blood pressure variations, such as e.g. vascular diseases.

In the so-called French Three-City study (Bordeaux-Dijon-Montpellier), the blood pressure was measured in 8801 participants at the beginning of the study (starting in 1999) and again about two years later. Outdoor temperatures on the day of measurement were obtained from local meteorological offices.

The researchers grouped around Annick Alpérovitch, M. D., at the National Health and Medical Research Institute in Paris (Institut National de la Santé et de la Récherche Médicale, Paris)  found a relationship between the measured blood pressure values and external temperature. Both systolic and diastolic blood pressure values differed significantly according to the distribution of outdoor temperature: Average systolic blood pressure was 5 mmHg higher in winter than in summer. High blood pressure, defined as a systolic blood pressure of 160 mmHg or higher, or a diastolic blood pressure of 95 mmHg or higher, was detected in 33.4 per cent of participants during winter and 23.8 percent during summer. These changes in blood pressure were greater in subjects over 80 years or older than in younger participants.

The authors explained that they could not demonstrate a causal link between high blood pressure and low external temperatures, yet they outlined that the observed relationship nevertheless had potentially important consequences for blood pressure management. This is particularly important in elderly people, in whom close monitoring of blood pressure and antihypertensive medication could be considered because they have a high risk of getting a stroke or an aneurysmal rupture.