Abstract 551: In a South Asian Population, Urbanization is an Independent Predictor of Arterial Stiffness in Men

Abstract

Background: Rapid urbanization is driving economies of South Asian countries. Here we use satellite based land cover data and distance to urban center (UC) to measure of the impact of urban environment on arterial stiffness (AS) in a population based study in South India. Methods: In a cross-sectional analysis, after exclusion of people with previous history of diabetes and hypertension, 6746 subjects (mean age 42 years; 54% women) spread over 78 kms from the UC constituted the study sample. MODIS satellite derived land cover data at a 1 km x 1 km resolution was obtained and joined to each participant's geolocated residential position in ArcGIS to assign urban and rural designations. The study included carotid-femoral pulse wave velocity (PWV) measurement using a high-fidelity applanation tonometry, blood pressure (BP), anthropometric, psychosocial, high sensitive C-reactive protein (HsCRP) and other biomarkers assessments. Results: Based on land cover analysis, participants in urban locations had a mean (SD) PWV (m/s) of 7.74 (1.65) compared to 7.6 (1.62) in rural locations (p= 0.002) [Fig 1], while there was no significant difference in HsCRP levels. In multiple regression analyses adjusting for age, smoking, BMI, BP, blood glucose, LDL, socioeconomic, anxiety and stress levels, distance from UC was independently associated with PWV in men (β = -0.007, p <0.001), but not in women. Standardized effect-estimates in the multi-linear regression model indicated that distance from UC had the third largest effect on PWV after age and BP. After multivariable adjustments, the largest effect of distance from UC on PWV was on non-smoking men age 46-75 years. Residing every 1 km further away from the UC corresponded with a -0.012 m/s (95%CI: -0.020, -0.003) decrease in PWV. Conclusions: Urbanization is an independent predictor of AS in men, more so in non-smoking older men. Further research will elucidate components in the urban environment that may be contributing to higher AS.