Cold weather can increase the risk of stroke: Study

A study by The George Institute for Global Health has shown that cold weather leads to a heightened risk of the most lethal form of stroke – intracranial hemorrahage (ICH), or bleeding inside the brain


NEW DELHI: The study conducted on over 1900 patients across the world between 2008 and 2012 found that almost 80 percent of the strokes occur when the temperature is below 20°C. It was also discovered that bleeding was more likely to occur during the first two to three hours of prolonged exposure to cold temperature.

Approximately 1.5 million people in India suffer a stroke every year, with 500,000 people living with stroke-related disability. It is estimated that the fatality rates of stroke sufferers is between 27 to 41 percent. The extreme cold weather conditions in the northern regions of India may be a major trigger for bleeding inside the brain. The studies have revealed that the cold conditions result in narrowing of blood vessels and increase the blood pressure, which causes bleeding.

Dr Vivekanand Jha, Executive Director, George Institute for Global Health, India said, “The burden of non-communicable diseases is continuously on the rise in India as indicated by the latest Global Burden of Disease data. It is time we woke up to the fact that stroke is fast becoming one of the leading causes of death and disability”.

“Bleeding in the brain tissue is a serious issue with a high mortality and disability rate. People living in the regions which face extreme cold are at a higher risk as their blood vessels contract, thereby increasing the blood pressure.” He added.

The study shows that there are over 5.3 million new cases of ICH and over 3 million ICH related deaths across the world every year. Patient records studied across 21 countries including India reveal that almost 70 percent people have had a known history of Blood Pressure. Patient data gathered from a previous trial conducted by The George Institute for Global Health revealed a new way to treat ICH. According to the trial results, intensive blood pressure lowering (<140 mmHg) in patients with ICH reduced the risk of disability and improved the recovery chances by almost 20%.

Looking at the severe burden of stroke related disabilities and deaths, The George Institute for Global Health along with the researchers from the University of Sydney are working to provide access to affordable and effective rehabilitation to stroke patients in India. Working with 12 reputed medical institutions across the country, the researchers have recruited more than 1200 stroke patients over a period of two years. The programme titled ‘ATTEND’ aims to promote effective home-based care for stroke patients by training the family members.

Other key findings:

  • When compared to rates of ICH at 20°C, (considered the optimal temperature) the odds of experiencing ICH rose to 137 per cent when temperatures dropped to 10°C.
  • At zero the oddsrose to 192 per cent, at minus 10°C the odds climbed 313 per cent, and at minus 20°C the odds of having an ICH when compared to the reference temperature (20°C) were 576 per cent higher.

Stroke Facts and Figures:

  • Around 17 million people suffer stroke each year around the world. (WHO)
  • The most lethal of all stroke subtypes is intracerebral haemorrhage.
  • Up to 40 per cent of patients will die within 30 days from ICH. (2014 UNSW study)