Clean Air Could Lower Hypertension Risk Among Indian Women, Study Finds

"A 10 μg/m³ increase in PM2.5 levels was linked to a 5.2% rise in hypertension prevalence, with black carbon and sulphate emerging as the most harmful components. Meeting India's Clean Air Program targets could lead to a 2.42% reduction in hypertension cases, while adhering to WHO air quality guidelines may lower the burden by 4.21%," the researchers reported in the International Journal of Epidemiology.

Air pollution is a major global risk factor for hypertension, yet epidemiological data remains limited in developing countries, particularly concerning indigenous health data and the specific composition of fine particulate matter (PM2.5). Hypertension, a leading risk factor for cardiovascular diseases, is especially concerning for women in their reproductive years. With the high levels of ambient air pollution in India, understanding its impact on hypertension is crucial for shaping effective public health policies.

To address this knowledge gap in India, Sagnik Dey from the Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, and colleagues used a logistic regression model to estimate the association between hypertension prevalence and long-term exposure to PM2.5 and its composition. The study focused on women of reproductive age (WRA, 15–49 years) and utilized data from the fifth round of the National Family Health Survey. The analysis was adjusted for confounders, and the moderating effects of socioeconomic indicators were explored through a multiplicative interaction with PM2.5.

The study led to the following findings:

• Hypertension prevalence increased by 5.2% for every 10 μg/m3 rise in ambient PM2.5 exposure.
• Significant moderating effects were observed between smokers and nonsmokers, and across various sociodemographic parameters.
• Among PM2.5 components, every interquartile range increase in black carbon (BC) and sulphate exposure was strongly linked to higher odds of hypertension than organic carbon and dust.
• Achieving the National Clean Air Program target could reduce hypertension prevalence by 2.42% while adhering to World Health Organization air quality guidelines could lower it by 4.21%.

"We found that increased ambient PM2.5 exposure is linked to a higher prevalence of hypertension among women of reproductive age in India," the researchers stated.

"The risk varies across different PM2.5 species, with black carbon and sulphate presenting higher risks. Meeting clean air targets could significantly reduce the hypertension burden in this population," they concluded.

Reference:

Singh, T., Chaudhary, E., Roy, A., Ghosh, S., & Dey, S. (2024). Meeting clean air targets could reduce the burden of hypertension among women of reproductive age in India. International Journal of Epidemiology, 54(1). https://doi.org/10.1093/ije/dyaf007