Cold weather may raise blood pressure in elderly. In new research French are suggesting that elderly people may be more at risk of suffering a stroke, heart attack or kidney failure in winter because cold weather may raise their blood pressure.
The researchers from the National Institute of Health and Medical Research in Paris say four decades of research has shown that blood pressure changes with the seasons, but very little has looked specifically at old people.
According to Dr. Annick Alperovitch and colleagues, even though their study does not demonstrate a causal link between blood pressure and external temperature, the observed relationship nevertheless has potentially important consequences for blood pressure management in the elderly.
Billions of adults around the world suffer from hypertension which increases a person's risk for stroke, heart failure, heart attack and kidney failure.
For their study the French team looked at the relationship between blood pressure and temperature in more than 8,800 men and women aged 65 or older from three French cities - they had their blood pressure measured at regular intervals in 1999 and again two years later - outdoor temperatures on the day of measurement were obtained from local meteorological offices.
The researchers found that both systolic and diastolic blood pressures differed across the four seasons and during varying outdoor temperatures and high blood pressure was detected in about a third of the volunteers during winter and a quarter in summer.
High blood pressure is defined as a systolic reading of 160 or higher or a diastolic reading above 95.
The researchers say on average, each person's blood pressure fell between the initial and follow-up measurements and the decrease was strongly linked to outdoor temperature, with the average systolic blood pressure 5 millimetres higher in winter than in summer.