Jyoti Singh (India Science Wire)
Air
pollution is emerging as one of the main risk factors for cardiovascular deaths
in developing countries, according to a new study. A large proportion of
cardiovascular disease events and mortality can be attributed to a small number
of modifiable risk factors. This cohort study has been carried out in 21
countries where the researchers have examined14 modifiable risk factors.
Approximately
70% of cardiovascular disease cases and deaths in the overall study population
were attributed to modifiable risk factors. The modifiable risk factors are tobacco
use, alcohol, diet, physical activity and sodium intake. Metabolic factors include
lipids, blood pressure, diabetes and obesity. Socioeconomic factors included are
education, symptoms of depression, besides household and ambient pollution.
The study highlighted
the importance of addressing both household and ambient air pollution to reduce
cardiovascular disease and death. “In the middle-income and low-income
countries exposure to both forms of air pollution is high. Ambient air
pollution is primarily associated with a higher risk of cardiovascular disease,
while indoor air pollution is strongly associated with a higher risk of death,”
said Dr Manmeet Kaur, Post Graduate Institute of Medical Education and
Research, Chandigarh while speaking with India Science Wire.
“Several
risk factors such as low education and indoor and outdoor air pollution that
were underappreciated in the past have turned out to be more important than
others,” said Philip Joseph, a joint lead author of the paper.
The study
included four high-income countries, twelve middle-income countries and five
low-income countries. In the study, the researchers examined associations of 14
modifiable risk factors with mortality and cardiovascular disease of 155722
participants without a prior history of cardiovascular disease. Out of these
participants, 35,793 were from India.
“In
developing countries women are more prone to cardiovascular diseases than men,
as being at home they encounter indoor pollution more than men. The particulate matter is found to be more indoors,” said Prof VR Kutty (Health Action by
People, Trivandrum).
The study
also points out that among the behavioural risk factors, tobacco had the
strongest association with cardiovascular disease, followed by physical inactivity
and a low-quality diet. Of the metabolic risk factors, hypertension was strongly
associated with cardiovascular disease followed by diabetes, elevated non-HDL
(High-Density Lipoprotein) cholesterol and increased waist-to-hip ratio. There
were other important factors that are associated with a higher risk of
cardiovascular disease like low education levels, symptoms of depression, low
grip strength and household pollution.
The study
also says that in high-income countries the risk of cardiovascular diseases is
highly associated with tobacco whereas in low-income countries the risk was
highest with low education levels. And the risk associated with diabetes was
highest in high-income countries and low-income countries both.
The research
paper has been published in the journal The Lancet and the research was led
by researchers of the Population Health Research Institute (PHRI) of McMaster
University and Hamilton Health Sciences in Hamilton, Canada.
