Secondhand smoke may increase the risk of stroke by about 30 per cent for nonsmokers, a new study has warned.
Researchers used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a population-based, longitudinal study investigating cardiovascular disease events and mortality endpoints among white (55 per cent) and African American (45 per cent) adults aged greater than 45 years in the US.
The researchers found that even after adjustment for other stroke factors such as hypertension, diabetes, and heart disease, the 30 per cent stroke risk for nonsmokers remained.
The current study included almost 22,000 participants (38 per cent African American, 45 per cent male) with 23 per cent reporting secondhand smoke (SHS) exposure in the past year. During the period of April 2003 to March 2012, 428 strokes were reported.
A further analysis of the type of stroke (ischemic vs hemorrhagic) was performed and showed that most strokes were due to blockage of blood flow to the brain (352 ischemic, 50 hemorrhagic, and 26 strokes of unknown subtype).
"Our findings suggest the possibility for adverse health outcomes such as stroke among nonsmokers exposed to SHS and add to the body of evidence supporting stricter smoking regulations," said lead author Angela M Malek of the Department of Public Health Sciences, Medical University of South Carolina, Charleston.
"Future research will need to investigate the role of cardiovascular disease risk factors in the association and explore potential exposure to additional environmental variables, such as ambient air pollutants, in relation to stroke," said Malek.
The study was published in the American Journal of Preventive Medicine.
