Increased cardiovascular risk due to systemic inflammatory changes and enhanced oxidative stress in urban Indian women

Abstract

The study was undertaken to elucidate the inflammation- and oxidative stress-mediated deterioration of cardiovascular health in urban women exposed to ambient air pollution from vehicular and industrial emissions. A total of 556 urban women (median age, 34 years) and 514 age-matched control women who resided in the rural areas were enrolled. Serum interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-8 (IL-8) were measured by enzyme-linked immunosorbent assay as markers of inflammation. Generation of reactive oxygen species (ROS) by leukocytes was measured by flow cytometry and erythrocytic superoxide dismutase (SOD) was measured by spectrophotometry. Hypertension was diagnosed following the Seventh Report of the Joint Committee. On the days of sampling, data about particulate matter of diameter less than 10 μm (PM10) in city was obtained from website of State Pollution Control Board and that in rural ambience was measured using real-time aerosol monitor. Compared with control, urban women were exposed to higher levels of ambient air pollution; their serum contained significantly higher levels of IL-6, IL-8, TNF-α, and CRP. ROS generation was increased by 49 % while SOD was depleted by 34.9 %. Urban women were more hypertensive compared to their rural counterparts. PM10 levels were positively associated with inflammatory markers, oxidative stress, and hypertension. Exposure to increased levels of ambient air pollution, which are much higher than the set standard levels, predisposes urban women to increased risk of deteriorating cardiovascular health. Systemic inflammation and oxidative stress are assumed to be the key players in this process.