Physical urban environment and cardiometabolic diseases in the five largest Bulgarian cities

This study investigated the associations between residential environmental characteristics and the prevalence of cardiometabolic diseases in the five largest Bulgarian cities. Representative cross-sectional survey data (N = 4640 adults) was collected in Sofia, Plovdiv, Varna, Burgas, and Ruse. Participants self-reported diagnosis or medication intake for hypertension, ischemic heart disease (IHD), stroke, and diabetes mellitus, as well as domestic burning of solid fuel and having a domestic garden. Residential addresses were linked to greenspace (overall vegetation level, tree cover, urban greenspace), bluespace, walkability, air pollution (NO₂), and traffic noise (L_den). In the 300 m buffer, bluespace presence was inversely associated with hypertension (odds ratio [OR] = 0.67; 95% CI: 0.45, 1.00), IHD (OR = 0.45; 95% CI: 0.21, 0.99), and diabetes (OR = 0.51; 95% CI: 0.25, 1.04). Higher walkability and tree cover were inversely associated with hypertension (OR _{per 2 units} = 0.85; 95% CI: 0.75, 0.96) and diabetes (OR _{per 10%} = 0.77; 95% CI: 0.62, 0.97), respectively. These associations were stronger in larger buffers. Solid fuel burning was associated with IHD (OR = 1.63; 95% CI: 1.07, 2.50). There was an indication of a positive association between aircraft L_den and both stroke and IHD. The direction of the associations for domestic gardens, NO₂, road traffic and railway L_den was counterintuitive. We detected some nonlinear associations. In conclusion, people living in urban neighborhoods that were more walkable, closer to bluespace, and greener had lower prevalence of cardiometabolic diseases, while solid fuel burning was associated with higher odds of cardiovascular diseases. Unexpected associations with some exposures may be due to unaccounted for urban fabric characteristics. This study is among the first assessing an understudied region in Southeastern Europe. Its findings have the potential to inform public discourse and provide evidence to support the implementation of urban design conducive to cardiometabolic health.