Associations between Greenness, Impervious Surface Area, and Nighttime Lights on Biomarkers of Vascular Aging in Chennai, India

Abstract

Background:India is undergoing rapid urbanization with simultaneous increases in the prevalence of cardiovascular disease (CVD). As urban areas become home to an increasing share of the world’s population, it is important to understand relationships between the built environment and progression towards CVD.Objective:We assessed associations between multiple measures of the built environment and biomarkers of early vascular aging (EVA) in the Population Study of Urban, Rural and Semiurban Regions for the Detection of Endovascular Disease and Prevalence of Risk Factors and Holistic Intervention Study (PURSE-HIS) in Chennai, India.Methods:We performed a cross-sectional analysis of 3,150 study participants. EVA biomarkers included systolic and diastolic blood pressure (SBP and DBP), central pulse pressure (cPP) and flow-mediated dilatation (FMD). Multiple approaches were used to assign residential exposure to factors of the built environment: Moderate Resolution Imaging Spectroradiometer (MODIS)-derived normalized difference vegetation index (NDVI), a measure of vegetation health and greenness; Landsat-derived impervious surface area (ISA); and Visible Infrared Imaging Radiometer Suite (VIIRS)-derived nighttime lights (NTL). Multivariable regression models were used to assess associations between each built environment measure and biomarkers of EVA, adjusting for age, body mass index (BMI), cooking fuel type, energy intake, sex, physical activity, smoking, socioeconomic status, and stress.Results:Residing in areas with higher ISA or NTL, or lower greenness, was significantly associated with elevated SBP, DBP, and cPP, and with lower FMD, adjusting for age, BMI, sex, smoking status, and other CVD risk factors. An interquartile range decrease in greenness had the largest increase in SBP [4.3 mmHg (95% CI: 2.9, 5.6)], DBP [1.2 mmHg (95% CI: 0.4, 2.0)] and cPP [3.1 mmHg (95% CI: 2.0, 4.1)], and the largest decrease in FMD [−1.5% (95%CI: −2.2%, −0.9%].Conclusion:Greenness, ISA, and NTL were associated with increased SBP, DBP, and cPP, and with reduced FMD, suggesting a possible additional EVA pathway for the relationship between urbanization and increased CVD prevalence in urban India. https://doi.org/10.1289/EHP541

Land-Use Change and Cardiometabolic Risk Factors in an Urbanizing Area of South India: A Population-Based Cohort Study

“…We estimated moderate increases in cardiometabolic risk factors in participants living in areas rapidly building up compared with areas where land use was stable. Our estimates for blood pressure were comparable to those from a cross-sectional study conducted in Chennai, India, evaluating the effect of residential surrounding greenness and impervious surfaces on markers of vascular aging (Lane et al 2017). Lane et al (2017) observed increases of 3.4% in SBP and of 1.5% in DBP for a 1-IQR decrease in NDVI.…”

“…Our estimates for blood pressure were comparable to those from a cross-sectional study conducted in Chennai, India, evaluating the effect of residential surrounding greenness and impervious surfaces on markers of vascular aging (Lane et al 2017). Lane et al (2017) observed increases of 3.4% in SBP and of 1.5% in DBP for a 1-IQR decrease in NDVI. A recent meta-analysis showed a decrease in DBP of 2 mmHg in participants with the highest greenspace exposure vs. the lowest, estimated from 9,695 participants of 12 studies conducted in HICs (Twohig-Bennett and Jones 2018).…”

“…Despite the growing literature on the health effects of greenspace exposure, or its converse-built-up areas consisting of non-vegetated, human-constructed elements-evidence from low-and middle-income countries (LMICs) remains limited (Corlin et al 2018;Lane et al 2017). Generalizability of findings from high-income countries (HICs) to LMICs is challenging due to different definitions of greenspace (Taylor and Hochuli 2017).…”

Effect of supplemental nutrition in pregnancy on offspring’s risk of cardiovascular disease in young adulthood: Long-term follow-up of a cluster trial from India

“…Vascular assessments were carried out using recommended guidelines, as described previously [19]. Blood pressure was measured on the right arm in the supine position using a validated oscillometric device (Model M5-I; Omron, Matsusaka, Japan) with appropriate cuff size.…”

“…Village urbanisation was quantified using nighttime light intensity (NTLI), a data product derived from satellite sensors that capture visible near-infrared emissions from the earth's surface, which has been used to measure urbanisation and predict cardio-metabolic risk in several settings, including APCAPs cohort participants [19,20]. Geocoded village boundaries were applied to 2012 data from the Defense Meteorological Satellite Program (Operational Linescan System) accurate to a 1-km resolution, such that NTLI values represent emissions from the village areas only.…”