Weather Changes Tied to Stroke

Stroke risk tied to weather changes like temperature increase

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) When it's chilly out, some people get worried about catching a cold, but how about having a stroke? New research suggests there may be a connection between weather and stroke risk.

The researchers analyzed weather data and data on stroke hospitalizations across the US.

These researchers found that a slight increase in temperature was associated with a slight drop in both the risk of being hospitalized and the risk of dying from a stroke.

"Seek medical care if one side of the body goes numb."

In ischemic stroke, a blood vessel that sends blood to the brain becomes blocked by a clot. Symptoms can include sudden numbness on one side of the body, confusion, dizziness, trouble seeing and trouble speaking.

According to the authors of this study, led by Judith H. Lichtman, PhD, MPH, of the Yale School of Public Health in New Haven, Connecticut, there have been some studies suggesting a relationship between stroke and the weather, but findings have not been consistent.

To further explore the topic, the researchers looked at data on average temperatures, the change in daily temperature and the dew point, or humidity, alongside data on stroke hospitalizations and deaths.

Using the Nationwide Inpatient Sample 2009-2010, Dr. Lichtman and team looked for hospitalizations due to ischemic stroke in adults aged 18 or older. In total, 134,510 strokes were identified in patients with an average age of 72 years old.

Using the National Climatic Data Center, the researchers looked at temperature and dew point in the counties where strokes occurred on the day of the event.

After analyzing the data, Dr. Lichtman and team found that each 1 degree Fahrenheit (F) increase in the average temperature was tied to a 0.86 percent drop in the odds of being hospitalized for a stroke. The temperature increase of 1 degree was also tied to a 1.1 percent drop in the odds of dying in the hospital after having a stroke.

The researchers also found a connection between temperature changes and humidity and an increase in the risk of being hospitalized due to a stroke, but not a connection between either and the risk of dying from a stroke.

"Larger daily temperature changes and higher average dew point were associated with higher stroke hospitalization, while lower average annual temperatures were associated with both hospitalization and mortality after stroke," explained Dr. Lichtman and team.

In a news release from the American Heart Association, Dr. Lichtman said that these weather changes might be stressors that could lead to an increased stroke risk.

"Further research is needed to understand these effects to develop prevention strategies for vulnerable populations during periods of extreme weather conditions," the researchers wrote.

This study was presented February 12 at the American Heart Association's International Stroke Conference.

Studies presented at conferences are considered preliminary until published in a peer-reviewed journal.

Review Date: 
February 20, 2014
Last Updated:
February 20, 2014